diff --git a/dom/html/HTMLAnchorElement.cpp b/dom/html/HTMLAnchorElement.cpp
index 139ad2e8dfc43c..609cae3caf171b 100644
--- a/dom/html/HTMLAnchorElement.cpp
+++ b/dom/html/HTMLAnchorElement.cpp
@@ -92,7 +92,7 @@ HTMLAnchorElement::TabIndexDefault()
 }
 
 void
-HTMLAnchorElement::GetItemValueText(nsAString& aValue)
+HTMLAnchorElement::GetItemValueText(DOMString& aValue)
 {
   GetHref(aValue);
 }
diff --git a/dom/html/HTMLAnchorElement.h b/dom/html/HTMLAnchorElement.h
index 1471fc552db055..fcb50177fb23db 100644
--- a/dom/html/HTMLAnchorElement.h
+++ b/dom/html/HTMLAnchorElement.h
@@ -105,7 +105,7 @@ class HTMLAnchorElement MOZ_FINAL : public nsGenericHTMLElement,
   {
     SetHTMLAttr(nsGkAtoms::target, aValue, rv);
   }
-  void GetDownload(nsString& aValue)
+  void GetDownload(DOMString& aValue)
   {
     GetHTMLAttr(nsGkAtoms::download, aValue);
   }
@@ -118,7 +118,7 @@ class HTMLAnchorElement MOZ_FINAL : public nsGenericHTMLElement,
   {
     SetHTMLAttr(nsGkAtoms::ping, aValue, rv);
   }
-  void GetRel(nsString& aValue)
+  void GetRel(DOMString& aValue)
   {
     GetHTMLAttr(nsGkAtoms::rel, aValue);
   }
@@ -127,7 +127,7 @@ class HTMLAnchorElement MOZ_FINAL : public nsGenericHTMLElement,
     SetHTMLAttr(nsGkAtoms::rel, aValue, rv);
   }
   nsDOMTokenList* RelList();
-  void GetHreflang(nsString& aValue)
+  void GetHreflang(DOMString& aValue)
   {
     GetHTMLAttr(nsGkAtoms::hreflang, aValue);
   }
@@ -135,7 +135,7 @@ class HTMLAnchorElement MOZ_FINAL : public nsGenericHTMLElement,
   {
     SetHTMLAttr(nsGkAtoms::hreflang, aValue, rv);
   }
-  void GetType(nsString& aValue)
+  void GetType(DOMString& aValue)
   {
     GetHTMLAttr(nsGkAtoms::type, aValue);
   }
@@ -179,7 +179,7 @@ class HTMLAnchorElement MOZ_FINAL : public nsGenericHTMLElement,
   using Link::SetHash;
 
   // The XPCOM URI decomposition attributes are fine for us
-  void GetCoords(nsString& aValue)
+  void GetCoords(DOMString& aValue)
   {
     GetHTMLAttr(nsGkAtoms::coords, aValue);
   }
@@ -187,7 +187,7 @@ class HTMLAnchorElement MOZ_FINAL : public nsGenericHTMLElement,
   {
     SetHTMLAttr(nsGkAtoms::coords, aValue, rv);
   }
-  void GetCharset(nsString& aValue)
+  void GetCharset(DOMString& aValue)
   {
     GetHTMLAttr(nsGkAtoms::charset, aValue);
   }
@@ -195,7 +195,7 @@ class HTMLAnchorElement MOZ_FINAL : public nsGenericHTMLElement,
   {
     SetHTMLAttr(nsGkAtoms::charset, aValue, rv);
   }
-  void GetName(nsString& aValue)
+  void GetName(DOMString& aValue)
   {
     GetHTMLAttr(nsGkAtoms::name, aValue);
   }
@@ -203,7 +203,7 @@ class HTMLAnchorElement MOZ_FINAL : public nsGenericHTMLElement,
   {
     SetHTMLAttr(nsGkAtoms::name, aValue, rv);
   }
-  void GetRev(nsString& aValue)
+  void GetRev(DOMString& aValue)
   {
     GetHTMLAttr(nsGkAtoms::rev, aValue);
   }
@@ -211,7 +211,7 @@ class HTMLAnchorElement MOZ_FINAL : public nsGenericHTMLElement,
   {
     SetHTMLAttr(nsGkAtoms::rev, aValue, rv);
   }
-  void GetShape(nsString& aValue)
+  void GetShape(DOMString& aValue)
   {
     GetHTMLAttr(nsGkAtoms::shape, aValue);
   }
@@ -227,7 +227,7 @@ class HTMLAnchorElement MOZ_FINAL : public nsGenericHTMLElement,
 protected:
   virtual ~HTMLAnchorElement();
 
-  virtual void GetItemValueText(nsAString& text) MOZ_OVERRIDE;
+  virtual void GetItemValueText(DOMString& text) MOZ_OVERRIDE;
   virtual void SetItemValueText(const nsAString& text) MOZ_OVERRIDE;
   virtual JSObject* WrapNode(JSContext *aCx) MOZ_OVERRIDE;
   nsRefPtr<nsDOMTokenList > mRelList;
diff --git a/dom/html/HTMLAreaElement.cpp b/dom/html/HTMLAreaElement.cpp
index c3cff228409d3c..dbc704d051e090 100644
--- a/dom/html/HTMLAreaElement.cpp
+++ b/dom/html/HTMLAreaElement.cpp
@@ -67,7 +67,7 @@ HTMLAreaElement::TabIndexDefault()
 }
 
 void
-HTMLAreaElement::GetItemValueText(nsAString& aValue)
+HTMLAreaElement::GetItemValueText(DOMString& aValue)
 {
   GetHref(aValue);
 }
diff --git a/dom/html/HTMLAreaElement.h b/dom/html/HTMLAreaElement.h
index a666346ad4f36c..9dad695bbc6203 100644
--- a/dom/html/HTMLAreaElement.h
+++ b/dom/html/HTMLAreaElement.h
@@ -117,7 +117,7 @@ class HTMLAreaElement MOZ_FINAL : public nsGenericHTMLElement,
     SetHTMLAttr(nsGkAtoms::ping, aPing, aError);
   }
   
-  void GetRel(nsString& aValue)
+  void GetRel(DOMString& aValue)
   {
     GetHTMLAttr(nsGkAtoms::rel, aValue);
   }
@@ -180,7 +180,7 @@ class HTMLAreaElement MOZ_FINAL : public nsGenericHTMLElement,
 
   virtual JSObject* WrapNode(JSContext* aCx) MOZ_OVERRIDE;
 
-  virtual void GetItemValueText(nsAString& text) MOZ_OVERRIDE;
+  virtual void GetItemValueText(DOMString& text) MOZ_OVERRIDE;
   virtual void SetItemValueText(const nsAString& text) MOZ_OVERRIDE;
   nsRefPtr<nsDOMTokenList > mRelList;
 };
diff --git a/dom/html/HTMLBodyElement.cpp b/dom/html/HTMLBodyElement.cpp
index f62217beb9831f..b131eb3f8aa3df 100644
--- a/dom/html/HTMLBodyElement.cpp
+++ b/dom/html/HTMLBodyElement.cpp
@@ -210,9 +210,9 @@ HTMLBodyElement::SetBackground(const nsAString& aBackground)
 NS_IMETHODIMP
 HTMLBodyElement::GetBackground(nsAString& aBackground)
 {
-  nsString background;
+  DOMString background;
   GetBackground(background);
-  aBackground = background;
+  background.ToString(aBackground);
   return NS_OK;
 }
 
@@ -227,9 +227,9 @@ HTMLBodyElement::SetVLink(const nsAString& aVLink)
 NS_IMETHODIMP
 HTMLBodyElement::GetVLink(nsAString& aVLink)
 {
-  nsString vLink;
+  DOMString vLink;
   GetVLink(vLink);
-  aVLink = vLink;
+  vLink.ToString(aVLink);
   return NS_OK;
 }
 
@@ -244,9 +244,9 @@ HTMLBodyElement::SetALink(const nsAString& aALink)
 NS_IMETHODIMP
 HTMLBodyElement::GetALink(nsAString& aALink)
 {
-  nsString aLink;
+  DOMString aLink;
   GetALink(aLink);
-  aALink = aLink;
+  aLink.ToString(aALink);
   return NS_OK;
 }
 
@@ -261,9 +261,9 @@ HTMLBodyElement::SetLink(const nsAString& aLink)
 NS_IMETHODIMP
 HTMLBodyElement::GetLink(nsAString& aLink)
 {
-  nsString link;
+  DOMString link;
   GetLink(link);
-  aLink = link;
+  link.ToString(aLink);
   return NS_OK;
 }
 
@@ -278,9 +278,9 @@ HTMLBodyElement::SetText(const nsAString& aText)
 NS_IMETHODIMP
 HTMLBodyElement::GetText(nsAString& aText)
 {
-  nsString text;
+  DOMString text;
   GetText(text);
-  aText = text;
+  text.ToString(aText);
   return NS_OK;
 }
 
@@ -295,9 +295,9 @@ HTMLBodyElement::SetBgColor(const nsAString& aBgColor)
 NS_IMETHODIMP
 HTMLBodyElement::GetBgColor(nsAString& aBgColor)
 {
-  nsString bgColor;
+  DOMString bgColor;
   GetBgColor(bgColor);
-  aBgColor = bgColor;
+  bgColor.ToString(aBgColor);
   return NS_OK;
 }
 
diff --git a/dom/html/HTMLBodyElement.h b/dom/html/HTMLBodyElement.h
index f646fa56845f31..608a7a0d205051 100644
--- a/dom/html/HTMLBodyElement.h
+++ b/dom/html/HTMLBodyElement.h
@@ -68,7 +68,7 @@ class HTMLBodyElement MOZ_FINAL : public nsGenericHTMLElement,
 #undef WINDOW_EVENT_HELPER
 #undef EVENT
 
-  void GetText(nsString& aText)
+  void GetText(DOMString& aText)
   {
     GetHTMLAttr(nsGkAtoms::text, aText);
   }
@@ -76,7 +76,7 @@ class HTMLBodyElement MOZ_FINAL : public nsGenericHTMLElement,
   {
     SetHTMLAttr(nsGkAtoms::text, aText, aError);
   }
-  void GetLink(nsString& aLink)
+  void GetLink(DOMString& aLink)
   {
     GetHTMLAttr(nsGkAtoms::link, aLink);
   }
@@ -84,7 +84,7 @@ class HTMLBodyElement MOZ_FINAL : public nsGenericHTMLElement,
   {
     SetHTMLAttr(nsGkAtoms::link, aLink, aError);
   }
-  void GetVLink(nsString& aVLink)
+  void GetVLink(DOMString& aVLink)
   {
     GetHTMLAttr(nsGkAtoms::vlink, aVLink);
   }
@@ -92,7 +92,7 @@ class HTMLBodyElement MOZ_FINAL : public nsGenericHTMLElement,
   {
     SetHTMLAttr(nsGkAtoms::vlink, aVLink, aError);
   }
-  void GetALink(nsString& aALink)
+  void GetALink(DOMString& aALink)
   {
     GetHTMLAttr(nsGkAtoms::alink, aALink);
   }
@@ -100,7 +100,7 @@ class HTMLBodyElement MOZ_FINAL : public nsGenericHTMLElement,
   {
     SetHTMLAttr(nsGkAtoms::alink, aALink, aError);
   }
-  void GetBgColor(nsString& aBgColor)
+  void GetBgColor(DOMString& aBgColor)
   {
     GetHTMLAttr(nsGkAtoms::bgcolor, aBgColor);
   }
@@ -108,7 +108,7 @@ class HTMLBodyElement MOZ_FINAL : public nsGenericHTMLElement,
   {
     SetHTMLAttr(nsGkAtoms::bgcolor, aBgColor, aError);
   }
-  void GetBackground(nsString& aBackground)
+  void GetBackground(DOMString& aBackground)
   {
     GetHTMLAttr(nsGkAtoms::background, aBackground);
   }
diff --git a/dom/html/HTMLDataElement.cpp b/dom/html/HTMLDataElement.cpp
index 91bc5cad933936..f835ee89af0d07 100644
--- a/dom/html/HTMLDataElement.cpp
+++ b/dom/html/HTMLDataElement.cpp
@@ -30,7 +30,7 @@ HTMLDataElement::WrapNode(JSContext* aCx)
 }
 
 void
-HTMLDataElement::GetItemValueText(nsAString& text)
+HTMLDataElement::GetItemValueText(DOMString& text)
 {
   GetValue(text);
 }
diff --git a/dom/html/HTMLDataElement.h b/dom/html/HTMLDataElement.h
index bcbb0fa059273a..c290b8d6b9826f 100644
--- a/dom/html/HTMLDataElement.h
+++ b/dom/html/HTMLDataElement.h
@@ -20,7 +20,7 @@ class HTMLDataElement MOZ_FINAL : public nsGenericHTMLElement
   explicit HTMLDataElement(already_AddRefed<mozilla::dom::NodeInfo>& aNodeInfo);
 
   // HTMLDataElement WebIDL
-  void GetValue(nsAString& aValue)
+  void GetValue(DOMString& aValue)
   {
     GetHTMLAttr(nsGkAtoms::value, aValue);
   }
@@ -30,7 +30,7 @@ class HTMLDataElement MOZ_FINAL : public nsGenericHTMLElement
     SetHTMLAttr(nsGkAtoms::value, aValue, aError);
   }
 
-  virtual void GetItemValueText(nsAString& text) MOZ_OVERRIDE;
+  virtual void GetItemValueText(DOMString& text) MOZ_OVERRIDE;
   virtual void SetItemValueText(const nsAString& text) MOZ_OVERRIDE;
   virtual nsresult Clone(mozilla::dom::NodeInfo* aNodeInfo, nsINode** aResult) const MOZ_OVERRIDE;
 
diff --git a/dom/html/HTMLDivElement.h b/dom/html/HTMLDivElement.h
index 06bdae5e7cf76a..a4e567cb53e3b7 100644
--- a/dom/html/HTMLDivElement.h
+++ b/dom/html/HTMLDivElement.h
@@ -27,9 +27,9 @@ class HTMLDivElement MOZ_FINAL : public nsGenericHTMLElement,
   // nsIDOMHTMLDivElement
   NS_IMETHOD GetAlign(nsAString& aAlign) MOZ_OVERRIDE
   {
-    nsString align;
+    DOMString align;
     GetAlign(align);
-    aAlign = align;
+    align.ToString(aAlign);
     return NS_OK;
   }
   NS_IMETHOD SetAlign(const nsAString& aAlign) MOZ_OVERRIDE
@@ -39,7 +39,7 @@ class HTMLDivElement MOZ_FINAL : public nsGenericHTMLElement,
     return rv.ErrorCode();
   }
 
-  void GetAlign(nsString& aAlign)
+  void GetAlign(DOMString& aAlign)
   {
     GetHTMLAttr(nsGkAtoms::align, aAlign);
   }
diff --git a/dom/html/HTMLFontElement.h b/dom/html/HTMLFontElement.h
index 70e949d917d133..1c53a0a87ceb9b 100644
--- a/dom/html/HTMLFontElement.h
+++ b/dom/html/HTMLFontElement.h
@@ -19,7 +19,7 @@ class HTMLFontElement MOZ_FINAL : public nsGenericHTMLElement
   {
   }
 
-  void GetColor(nsString& aColor)
+  void GetColor(DOMString& aColor)
   {
     GetHTMLAttr(nsGkAtoms::color, aColor);
   }
@@ -27,7 +27,7 @@ class HTMLFontElement MOZ_FINAL : public nsGenericHTMLElement
   {
     SetHTMLAttr(nsGkAtoms::color, aColor, aError);
   }
-  void GetFace(nsString& aFace)
+  void GetFace(DOMString& aFace)
   {
     GetHTMLAttr(nsGkAtoms::face, aFace);
   }
@@ -35,7 +35,7 @@ class HTMLFontElement MOZ_FINAL : public nsGenericHTMLElement
   {
     SetHTMLAttr(nsGkAtoms::face, aFace, aError);
   }
-  void GetSize(nsString& aSize)
+  void GetSize(DOMString& aSize)
   {
     GetHTMLAttr(nsGkAtoms::size, aSize);
   }
diff --git a/dom/html/HTMLFrameSetElement.cpp b/dom/html/HTMLFrameSetElement.cpp
index 76ae4a9027ebf4..e1090b79d2ea89 100644
--- a/dom/html/HTMLFrameSetElement.cpp
+++ b/dom/html/HTMLFrameSetElement.cpp
@@ -39,9 +39,9 @@ HTMLFrameSetElement::SetCols(const nsAString& aCols)
 NS_IMETHODIMP
 HTMLFrameSetElement::GetCols(nsAString& aCols)
 {
-  nsString cols;
+  DOMString cols;
   GetCols(cols);
-  aCols = cols;
+  cols.ToString(aCols);
   return NS_OK;
 }
 
@@ -56,9 +56,9 @@ HTMLFrameSetElement::SetRows(const nsAString& aRows)
 NS_IMETHODIMP
 HTMLFrameSetElement::GetRows(nsAString& aRows)
 {
-  nsString rows;
+  DOMString rows;
   GetRows(rows);
-  aRows = rows;
+  rows.ToString(aRows);
   return NS_OK;
 }
 
diff --git a/dom/html/HTMLFrameSetElement.h b/dom/html/HTMLFrameSetElement.h
index 42dfd63051c8cb..f1fb399e9c4371 100644
--- a/dom/html/HTMLFrameSetElement.h
+++ b/dom/html/HTMLFrameSetElement.h
@@ -63,7 +63,7 @@ class HTMLFrameSetElement MOZ_FINAL : public nsGenericHTMLElement,
   // nsIDOMHTMLFrameSetElement
   NS_DECL_NSIDOMHTMLFRAMESETELEMENT
 
-  void GetCols(nsString& aCols)
+  void GetCols(DOMString& aCols)
   {
     GetHTMLAttr(nsGkAtoms::cols, aCols);
   }
@@ -71,7 +71,7 @@ class HTMLFrameSetElement MOZ_FINAL : public nsGenericHTMLElement,
   {
     SetHTMLAttr(nsGkAtoms::cols, aCols, aError);
   }
-  void GetRows(nsString& aRows)
+  void GetRows(DOMString& aRows)
   {
     GetHTMLAttr(nsGkAtoms::rows, aRows);
   }
diff --git a/dom/html/HTMLIFrameElement.cpp b/dom/html/HTMLIFrameElement.cpp
index 60f200d695fe50..312402a53f9f87 100644
--- a/dom/html/HTMLIFrameElement.cpp
+++ b/dom/html/HTMLIFrameElement.cpp
@@ -46,7 +46,7 @@ NS_IMPL_BOOL_ATTR(HTMLIFrameElement, AllowFullscreen, allowfullscreen)
 NS_IMPL_STRING_ATTR(HTMLIFrameElement, Srcdoc, srcdoc)
 
 void
-HTMLIFrameElement::GetItemValueText(nsAString& aValue)
+HTMLIFrameElement::GetItemValueText(DOMString& aValue)
 {
   GetSrc(aValue);
 }
diff --git a/dom/html/HTMLIFrameElement.h b/dom/html/HTMLIFrameElement.h
index 4b3560c1162512..2a6af020961d86 100644
--- a/dom/html/HTMLIFrameElement.h
+++ b/dom/html/HTMLIFrameElement.h
@@ -177,7 +177,7 @@ class HTMLIFrameElement MOZ_FINAL : public nsGenericHTMLFrameElement
 protected:
   virtual ~HTMLIFrameElement();
 
-  virtual void GetItemValueText(nsAString& text) MOZ_OVERRIDE;
+  virtual void GetItemValueText(DOMString& text) MOZ_OVERRIDE;
   virtual void SetItemValueText(const nsAString& text) MOZ_OVERRIDE;
 
   virtual JSObject* WrapNode(JSContext* aCx) MOZ_OVERRIDE;
diff --git a/dom/html/HTMLImageElement.cpp b/dom/html/HTMLImageElement.cpp
index 7caf2c6b4ffc96..76ff1d8f40cbc2 100644
--- a/dom/html/HTMLImageElement.cpp
+++ b/dom/html/HTMLImageElement.cpp
@@ -181,7 +181,7 @@ HTMLImageElement::GetCurrentSrc(nsAString& aValue)
 }
 
 void
-HTMLImageElement::GetItemValueText(nsAString& aValue)
+HTMLImageElement::GetItemValueText(DOMString& aValue)
 {
   GetSrc(aValue);
 }
diff --git a/dom/html/HTMLImageElement.h b/dom/html/HTMLImageElement.h
index 408353d8163c63..47cf8ae6b7dddf 100644
--- a/dom/html/HTMLImageElement.h
+++ b/dom/html/HTMLImageElement.h
@@ -311,7 +311,7 @@ class HTMLImageElement MOZ_FINAL : public nsGenericHTMLElement,
                                    const nsAString *aSizes = nullptr);
 
   CSSIntPoint GetXY();
-  virtual void GetItemValueText(nsAString& text) MOZ_OVERRIDE;
+  virtual void GetItemValueText(DOMString& text) MOZ_OVERRIDE;
   virtual void SetItemValueText(const nsAString& text) MOZ_OVERRIDE;
   virtual JSObject* WrapNode(JSContext *aCx) MOZ_OVERRIDE;
   void UpdateFormOwner();
diff --git a/dom/html/HTMLLIElement.h b/dom/html/HTMLLIElement.h
index daf84e2ef3f9d2..27a250d5aa7ad2 100644
--- a/dom/html/HTMLLIElement.h
+++ b/dom/html/HTMLLIElement.h
@@ -38,7 +38,7 @@ class HTMLLIElement MOZ_FINAL : public nsGenericHTMLElement,
   virtual nsresult Clone(mozilla::dom::NodeInfo *aNodeInfo, nsINode **aResult) const MOZ_OVERRIDE;
 
   // WebIDL API
-  void GetType(nsString& aType)
+  void GetType(DOMString& aType)
   {
     GetHTMLAttr(nsGkAtoms::type, aType);
   }
diff --git a/dom/html/HTMLLegendElement.h b/dom/html/HTMLLegendElement.h
index 78b17407b797b8..67df4d62bfbff3 100644
--- a/dom/html/HTMLLegendElement.h
+++ b/dom/html/HTMLLegendElement.h
@@ -67,7 +67,7 @@ class HTMLLegendElement MOZ_FINAL : public nsGenericHTMLElement
 
   already_AddRefed<HTMLFormElement> GetForm();
 
-  void GetAlign(nsAString& aAlign)
+  void GetAlign(DOMString& aAlign)
   {
     GetHTMLAttr(nsGkAtoms::align, aAlign);
   }
diff --git a/dom/html/HTMLLinkElement.cpp b/dom/html/HTMLLinkElement.cpp
index 0b812412f9795f..95442e803b8038 100644
--- a/dom/html/HTMLLinkElement.cpp
+++ b/dom/html/HTMLLinkElement.cpp
@@ -119,7 +119,7 @@ NS_IMPL_STRING_ATTR(HTMLLinkElement, Target, target)
 NS_IMPL_STRING_ATTR(HTMLLinkElement, Type, type)
 
 void
-HTMLLinkElement::GetItemValueText(nsAString& aValue)
+HTMLLinkElement::GetItemValueText(DOMString& aValue)
 {
   GetHref(aValue);
 }
diff --git a/dom/html/HTMLLinkElement.h b/dom/html/HTMLLinkElement.h
index 0d44af25beddb6..5461cbdaf1f574 100644
--- a/dom/html/HTMLLinkElement.h
+++ b/dom/html/HTMLLinkElement.h
@@ -161,7 +161,7 @@ class HTMLLinkElement MOZ_FINAL : public nsGenericHTMLElement,
   virtual CORSMode GetCORSMode() const MOZ_OVERRIDE;
 protected:
   // nsGenericHTMLElement
-  virtual void GetItemValueText(nsAString& text) MOZ_OVERRIDE;
+  virtual void GetItemValueText(DOMString& text) MOZ_OVERRIDE;
   virtual void SetItemValueText(const nsAString& text) MOZ_OVERRIDE;
   nsRefPtr<nsDOMTokenList > mRelList;
 private:
diff --git a/dom/html/HTMLMediaElement.cpp b/dom/html/HTMLMediaElement.cpp
index 260e637cbe3dc5..ddc4db361a2baa 100644
--- a/dom/html/HTMLMediaElement.cpp
+++ b/dom/html/HTMLMediaElement.cpp
@@ -2141,7 +2141,7 @@ HTMLMediaElement::~HTMLMediaElement()
 }
 
 void
-HTMLMediaElement::GetItemValueText(nsAString& aValue)
+HTMLMediaElement::GetItemValueText(DOMString& aValue)
 {
   // Can't call GetSrc because we don't have a JSContext
   GetURIAttr(nsGkAtoms::src, nullptr, aValue);
diff --git a/dom/html/HTMLMediaElement.h b/dom/html/HTMLMediaElement.h
index a2bd15458bf45a..8d583ef00fbb71 100644
--- a/dom/html/HTMLMediaElement.h
+++ b/dom/html/HTMLMediaElement.h
@@ -632,7 +632,7 @@ class HTMLMediaElement : public nsGenericHTMLElement,
   class MediaStreamTracksAvailableCallback;
   class StreamListener;
 
-  virtual void GetItemValueText(nsAString& text) MOZ_OVERRIDE;
+  virtual void GetItemValueText(DOMString& text) MOZ_OVERRIDE;
   virtual void SetItemValueText(const nsAString& text) MOZ_OVERRIDE;
 
   class WakeLockBoolWrapper {
diff --git a/dom/html/HTMLMetaElement.cpp b/dom/html/HTMLMetaElement.cpp
index 93f1c82459d160..09368466b867d2 100644
--- a/dom/html/HTMLMetaElement.cpp
+++ b/dom/html/HTMLMetaElement.cpp
@@ -36,7 +36,7 @@ NS_IMPL_STRING_ATTR(HTMLMetaElement, Name, name)
 NS_IMPL_STRING_ATTR(HTMLMetaElement, Scheme, scheme)
 
 void
-HTMLMetaElement::GetItemValueText(nsAString& aValue)
+HTMLMetaElement::GetItemValueText(DOMString& aValue)
 {
   GetContent(aValue);
 }
diff --git a/dom/html/HTMLMetaElement.h b/dom/html/HTMLMetaElement.h
index a1764af4f5cd9f..8e10f1440dea07 100644
--- a/dom/html/HTMLMetaElement.h
+++ b/dom/html/HTMLMetaElement.h
@@ -64,7 +64,7 @@ class HTMLMetaElement MOZ_FINAL : public nsGenericHTMLElement,
 protected:
   virtual ~HTMLMetaElement();
 
-  virtual void GetItemValueText(nsAString& text) MOZ_OVERRIDE;
+  virtual void GetItemValueText(DOMString& text) MOZ_OVERRIDE;
   virtual void SetItemValueText(const nsAString& text) MOZ_OVERRIDE;
 };
 
diff --git a/dom/html/HTMLModElement.h b/dom/html/HTMLModElement.h
index 370e8e96166a44..85209902a2b088 100644
--- a/dom/html/HTMLModElement.h
+++ b/dom/html/HTMLModElement.h
@@ -28,7 +28,7 @@ class HTMLModElement MOZ_FINAL : public nsGenericHTMLElement
   {
     SetHTMLAttr(nsGkAtoms::cite, aCite, aRv);
   }
-  void GetDateTime(nsAString& aDateTime)
+  void GetDateTime(DOMString& aDateTime)
   {
     GetHTMLAttr(nsGkAtoms::datetime, aDateTime);
   }
diff --git a/dom/html/HTMLObjectElement.cpp b/dom/html/HTMLObjectElement.cpp
index e08a1ca9a84878..be515683db67b3 100644
--- a/dom/html/HTMLObjectElement.cpp
+++ b/dom/html/HTMLObjectElement.cpp
@@ -111,7 +111,7 @@ HTMLObjectElement::GetForm(nsIDOMHTMLFormElement **aForm)
 }
 
 void
-HTMLObjectElement::GetItemValueText(nsAString& aValue)
+HTMLObjectElement::GetItemValueText(DOMString& aValue)
 {
   GetData(aValue);
 }
diff --git a/dom/html/HTMLObjectElement.h b/dom/html/HTMLObjectElement.h
index 5f074592851f0f..9943c131b5f29b 100644
--- a/dom/html/HTMLObjectElement.h
+++ b/dom/html/HTMLObjectElement.h
@@ -235,7 +235,7 @@ class HTMLObjectElement MOZ_FINAL : public nsGenericHTMLFormElement
    */
   bool IsFocusableForTabIndex();
   
-  virtual void GetItemValueText(nsAString& text) MOZ_OVERRIDE;
+  virtual void GetItemValueText(DOMString& text) MOZ_OVERRIDE;
   virtual void SetItemValueText(const nsAString& text) MOZ_OVERRIDE;
 
   virtual ~HTMLObjectElement();
diff --git a/dom/html/HTMLSharedListElement.h b/dom/html/HTMLSharedListElement.h
index 44f3fc57467c7b..1217d7f5c5f230 100644
--- a/dom/html/HTMLSharedListElement.h
+++ b/dom/html/HTMLSharedListElement.h
@@ -58,7 +58,7 @@ class HTMLSharedListElement MOZ_FINAL : public nsGenericHTMLElement,
   {
     SetHTMLIntAttr(nsGkAtoms::start, aStart, rv);
   }
-  void GetType(nsString& aType)
+  void GetType(DOMString& aType)
   {
     GetHTMLAttr(nsGkAtoms::type, aType);
   }
diff --git a/dom/html/HTMLSharedObjectElement.cpp b/dom/html/HTMLSharedObjectElement.cpp
index 12b4e6e95e5d65..744732e906de90 100644
--- a/dom/html/HTMLSharedObjectElement.cpp
+++ b/dom/html/HTMLSharedObjectElement.cpp
@@ -36,7 +36,7 @@ HTMLSharedObjectElement::HTMLSharedObjectElement(already_AddRefed<mozilla::dom::
 }
 
 void
-HTMLSharedObjectElement::GetItemValueText(nsAString& aValue)
+HTMLSharedObjectElement::GetItemValueText(DOMString& aValue)
 {
   if (mNodeInfo->Equals(nsGkAtoms::applet)) {
     nsGenericHTMLElement::GetItemValueText(aValue);
diff --git a/dom/html/HTMLSharedObjectElement.h b/dom/html/HTMLSharedObjectElement.h
index 16a29699c136ac..c09caf3e3df3e6 100644
--- a/dom/html/HTMLSharedObjectElement.h
+++ b/dom/html/HTMLSharedObjectElement.h
@@ -206,7 +206,7 @@ class HTMLSharedObjectElement MOZ_FINAL : public nsGenericHTMLElement
   // always true for <embed>, per the documentation in nsIContent.h.
   bool mIsDoneAddingChildren;
 
-  virtual void GetItemValueText(nsAString& text) MOZ_OVERRIDE;
+  virtual void GetItemValueText(DOMString& text) MOZ_OVERRIDE;
   virtual void SetItemValueText(const nsAString& text) MOZ_OVERRIDE;
 
   virtual JSObject* WrapNode(JSContext *aCx) MOZ_OVERRIDE;
diff --git a/dom/html/HTMLSourceElement.cpp b/dom/html/HTMLSourceElement.cpp
index 7ea2efbd727702..ebc0a581940440 100644
--- a/dom/html/HTMLSourceElement.cpp
+++ b/dom/html/HTMLSourceElement.cpp
@@ -121,7 +121,7 @@ HTMLSourceElement::AfterSetAttr(int32_t aNameSpaceID, nsIAtom* aName,
 }
 
 void
-HTMLSourceElement::GetItemValueText(nsAString& aValue)
+HTMLSourceElement::GetItemValueText(DOMString& aValue)
 {
   GetSrc(aValue);
 }
diff --git a/dom/html/HTMLSourceElement.h b/dom/html/HTMLSourceElement.h
index 8035a8d8c4d691..0dffaeb0f1caae 100644
--- a/dom/html/HTMLSourceElement.h
+++ b/dom/html/HTMLSourceElement.h
@@ -60,7 +60,7 @@ class HTMLSourceElement MOZ_FINAL : public nsGenericHTMLElement,
     SetHTMLAttr(nsGkAtoms::src, aSrc, rv);
   }
 
-  void GetType(nsString& aType)
+  void GetType(DOMString& aType)
   {
     GetHTMLAttr(nsGkAtoms::type, aType);
   }
@@ -69,7 +69,7 @@ class HTMLSourceElement MOZ_FINAL : public nsGenericHTMLElement,
     SetHTMLAttr(nsGkAtoms::type, aType, rv);
   }
 
-  void GetSrcset(nsString& aSrcset)
+  void GetSrcset(DOMString& aSrcset)
   {
     GetHTMLAttr(nsGkAtoms::srcset, aSrcset);
   }
@@ -78,7 +78,7 @@ class HTMLSourceElement MOZ_FINAL : public nsGenericHTMLElement,
     SetHTMLAttr(nsGkAtoms::srcset, aSrcset, rv);
   }
 
-  void GetSizes(nsString& aSizes)
+  void GetSizes(DOMString& aSizes)
   {
     GetHTMLAttr(nsGkAtoms::sizes, aSizes);
   }
@@ -87,7 +87,7 @@ class HTMLSourceElement MOZ_FINAL : public nsGenericHTMLElement,
     SetHTMLAttr(nsGkAtoms::sizes, aSizes, rv);
   }
 
-  void GetMedia(nsString& aMedia)
+  void GetMedia(DOMString& aMedia)
   {
     GetHTMLAttr(nsGkAtoms::media, aMedia);
   }
@@ -102,7 +102,7 @@ class HTMLSourceElement MOZ_FINAL : public nsGenericHTMLElement,
   virtual JSObject* WrapNode(JSContext* aCx) MOZ_OVERRIDE;
 
 protected:
-  virtual void GetItemValueText(nsAString& text) MOZ_OVERRIDE;
+  virtual void GetItemValueText(DOMString& text) MOZ_OVERRIDE;
   virtual void SetItemValueText(const nsAString& text) MOZ_OVERRIDE;
 
   virtual nsresult AfterSetAttr(int32_t aNameSpaceID, nsIAtom* aName,
diff --git a/dom/html/HTMLTableCaptionElement.h b/dom/html/HTMLTableCaptionElement.h
index fbad82d94eb693..704013876fe585 100644
--- a/dom/html/HTMLTableCaptionElement.h
+++ b/dom/html/HTMLTableCaptionElement.h
@@ -28,7 +28,7 @@ class HTMLTableCaptionElement MOZ_FINAL : public nsGenericHTMLElement,
   // nsIDOMHTMLTableCaptionElement
   NS_DECL_NSIDOMHTMLTABLECAPTIONELEMENT
 
-  void GetAlign(nsString& aAlign)
+  void GetAlign(DOMString& aAlign)
   {
     GetHTMLAttr(nsGkAtoms::align, aAlign);
   }
diff --git a/dom/html/HTMLTableCellElement.cpp b/dom/html/HTMLTableCellElement.cpp
index 2092aa33235f40..1f18bac477d503 100644
--- a/dom/html/HTMLTableCellElement.cpp
+++ b/dom/html/HTMLTableCellElement.cpp
@@ -127,9 +127,9 @@ HTMLTableCellElement::SetAbbr(const nsAString& aAbbr)
 NS_IMETHODIMP
 HTMLTableCellElement::GetAbbr(nsAString& aAbbr)
 {
-  nsString abbr;
+  DOMString abbr;
   GetAbbr(abbr);
-  aAbbr = abbr;
+  abbr.ToString(aAbbr);
   return NS_OK;
 }
 
@@ -144,9 +144,9 @@ HTMLTableCellElement::SetAxis(const nsAString& aAxis)
 NS_IMETHODIMP
 HTMLTableCellElement::GetAxis(nsAString& aAxis)
 {
-  nsString axis;
+  DOMString axis;
   GetAxis(axis);
-  aAxis = axis;
+  axis.ToString(aAxis);
   return NS_OK;
 }
 
@@ -161,9 +161,9 @@ HTMLTableCellElement::SetAlign(const nsAString& aAlign)
 NS_IMETHODIMP
 HTMLTableCellElement::GetAlign(nsAString& aAlign)
 {
-  nsString align;
+  DOMString align;
   GetAlign(align);
-  aAlign = align;
+  align.ToString(aAlign);
   return NS_OK;
 }
 
@@ -178,9 +178,9 @@ HTMLTableCellElement::SetVAlign(const nsAString& aVAlign)
 NS_IMETHODIMP
 HTMLTableCellElement::GetVAlign(nsAString& aVAlign)
 {
-  nsString vAlign;
+  DOMString vAlign;
   GetVAlign(vAlign);
-  aVAlign = vAlign;
+  vAlign.ToString(aVAlign);
   return NS_OK;
 }
 
@@ -195,9 +195,9 @@ HTMLTableCellElement::SetCh(const nsAString& aCh)
 NS_IMETHODIMP
 HTMLTableCellElement::GetCh(nsAString& aCh)
 {
-  nsString ch;
+  DOMString ch;
   GetCh(ch);
-  aCh = ch;
+  ch.ToString(aCh);
   return NS_OK;
 }
 
@@ -212,9 +212,9 @@ HTMLTableCellElement::SetChOff(const nsAString& aChOff)
 NS_IMETHODIMP
 HTMLTableCellElement::GetChOff(nsAString& aChOff)
 {
-  nsString chOff;
+  DOMString chOff;
   GetChOff(chOff);
-  aChOff = chOff;
+  chOff.ToString(aChOff);
   return NS_OK;
 }
 
@@ -229,9 +229,9 @@ HTMLTableCellElement::SetBgColor(const nsAString& aBgColor)
 NS_IMETHODIMP
 HTMLTableCellElement::GetBgColor(nsAString& aBgColor)
 {
-  nsString bgColor;
+  DOMString bgColor;
   GetBgColor(bgColor);
-  aBgColor = bgColor;
+  bgColor.ToString(aBgColor);
   return NS_OK;
 }
 
@@ -246,9 +246,9 @@ HTMLTableCellElement::SetHeight(const nsAString& aHeight)
 NS_IMETHODIMP
 HTMLTableCellElement::GetHeight(nsAString& aHeight)
 {
-  nsString height;
+  DOMString height;
   GetHeight(height);
-  aHeight = height;
+  height.ToString(aHeight);
   return NS_OK;
 }
 
@@ -263,9 +263,9 @@ HTMLTableCellElement::SetWidth(const nsAString& aWidth)
 NS_IMETHODIMP
 HTMLTableCellElement::GetWidth(nsAString& aWidth)
 {
-  nsString width;
+  DOMString width;
   GetWidth(width);
-  aWidth = width;
+  width.ToString(aWidth);
   return NS_OK;
 }
 
@@ -295,9 +295,9 @@ HTMLTableCellElement::SetScope(const nsAString& aScope)
 NS_IMETHODIMP
 HTMLTableCellElement::GetScope(nsAString& aScope)
 {
-  nsString scope;
+  DOMString scope;
   GetScope(scope);
-  aScope = scope;
+  scope.ToString(aScope);
   return NS_OK;
 }
 
@@ -312,9 +312,9 @@ HTMLTableCellElement::SetHeaders(const nsAString& aHeaders)
 NS_IMETHODIMP
 HTMLTableCellElement::GetHeaders(nsAString& aHeaders)
 {
-  nsString headers;
+  DOMString headers;
   GetHeaders(headers);
-  aHeaders = headers;
+  headers.ToString(aHeaders);
   return NS_OK;
 }
 
@@ -349,7 +349,7 @@ HTMLTableCellElement::GetRowSpan(int32_t* aRowSpan)
 }
 
 void
-HTMLTableCellElement::GetAlign(nsString& aValue)
+HTMLTableCellElement::GetAlign(DOMString& aValue)
 {
   if (!GetAttr(kNameSpaceID_None, nsGkAtoms::align, aValue)) {
     // There's no align attribute, ask the row for the alignment.
diff --git a/dom/html/HTMLTableCellElement.h b/dom/html/HTMLTableCellElement.h
index 71532056d1387b..abad21432700d3 100644
--- a/dom/html/HTMLTableCellElement.h
+++ b/dom/html/HTMLTableCellElement.h
@@ -49,7 +49,7 @@ class HTMLTableCellElement MOZ_FINAL : public nsGenericHTMLElement,
     SetHTMLIntAttr(nsGkAtoms::rowspan, aRowSpan, aError);
   }
   //already_AddRefed<nsDOMSettableTokenList> Headers() const;
-  void GetHeaders(nsString& aHeaders)
+  void GetHeaders(DOMString& aHeaders)
   {
     GetHTMLAttr(nsGkAtoms::headers, aHeaders);
   }
@@ -59,7 +59,7 @@ class HTMLTableCellElement MOZ_FINAL : public nsGenericHTMLElement,
   }
   int32_t CellIndex() const;
 
-  void GetAbbr(nsString& aAbbr)
+  void GetAbbr(DOMString& aAbbr)
   {
     GetHTMLAttr(nsGkAtoms::abbr, aAbbr);
   }
@@ -67,7 +67,7 @@ class HTMLTableCellElement MOZ_FINAL : public nsGenericHTMLElement,
   {
     SetHTMLAttr(nsGkAtoms::abbr, aAbbr, aError);
   }
-  void GetScope(nsString& aScope)
+  void GetScope(DOMString& aScope)
   {
     GetHTMLAttr(nsGkAtoms::scope, aScope);
   }
@@ -75,12 +75,12 @@ class HTMLTableCellElement MOZ_FINAL : public nsGenericHTMLElement,
   {
     SetHTMLAttr(nsGkAtoms::scope, aScope, aError);
   }
-  void GetAlign(nsString& aAlign);
+  void GetAlign(DOMString& aAlign);
   void SetAlign(const nsAString& aAlign, ErrorResult& aError)
   {
     SetHTMLAttr(nsGkAtoms::align, aAlign, aError);
   }
-  void GetAxis(nsString& aAxis)
+  void GetAxis(DOMString& aAxis)
   {
     GetHTMLAttr(nsGkAtoms::axis, aAxis);
   }
@@ -88,7 +88,7 @@ class HTMLTableCellElement MOZ_FINAL : public nsGenericHTMLElement,
   {
     SetHTMLAttr(nsGkAtoms::axis, aAxis, aError);
   }
-  void GetHeight(nsString& aHeight)
+  void GetHeight(DOMString& aHeight)
   {
     GetHTMLAttr(nsGkAtoms::height, aHeight);
   }
@@ -96,7 +96,7 @@ class HTMLTableCellElement MOZ_FINAL : public nsGenericHTMLElement,
   {
     SetHTMLAttr(nsGkAtoms::height, aHeight, aError);
   }
-  void GetWidth(nsString& aWidth)
+  void GetWidth(DOMString& aWidth)
   {
     GetHTMLAttr(nsGkAtoms::width, aWidth);
   }
@@ -104,7 +104,7 @@ class HTMLTableCellElement MOZ_FINAL : public nsGenericHTMLElement,
   {
     SetHTMLAttr(nsGkAtoms::width, aWidth, aError);
   }
-  void GetCh(nsString& aCh)
+  void GetCh(DOMString& aCh)
   {
     GetHTMLAttr(nsGkAtoms::_char, aCh);
   }
@@ -112,7 +112,7 @@ class HTMLTableCellElement MOZ_FINAL : public nsGenericHTMLElement,
   {
     SetHTMLAttr(nsGkAtoms::_char, aCh, aError);
   }
-  void GetChOff(nsString& aChOff)
+  void GetChOff(DOMString& aChOff)
   {
     GetHTMLAttr(nsGkAtoms::charoff, aChOff);
   }
@@ -128,7 +128,7 @@ class HTMLTableCellElement MOZ_FINAL : public nsGenericHTMLElement,
   {
     SetHTMLBoolAttr(nsGkAtoms::nowrap, aNoWrap, aError);
   }
-  void GetVAlign(nsString& aVAlign)
+  void GetVAlign(DOMString& aVAlign)
   {
     GetHTMLAttr(nsGkAtoms::valign, aVAlign);
   }
@@ -136,7 +136,7 @@ class HTMLTableCellElement MOZ_FINAL : public nsGenericHTMLElement,
   {
     SetHTMLAttr(nsGkAtoms::valign, aVAlign, aError);
   }
-  void GetBgColor(nsString& aBgColor)
+  void GetBgColor(DOMString& aBgColor)
   {
     GetHTMLAttr(nsGkAtoms::bgcolor, aBgColor);
   }
diff --git a/dom/html/HTMLTableColElement.h b/dom/html/HTMLTableColElement.h
index 64c6bb70d9041c..dfa247d5f8caa0 100644
--- a/dom/html/HTMLTableColElement.h
+++ b/dom/html/HTMLTableColElement.h
@@ -29,7 +29,7 @@ class HTMLTableColElement MOZ_FINAL : public nsGenericHTMLElement
     SetHTMLIntAttr(nsGkAtoms::span, aSpan, aError);
   }
 
-  void GetAlign(nsString& aAlign)
+  void GetAlign(DOMString& aAlign)
   {
     GetHTMLAttr(nsGkAtoms::align, aAlign);
   }
@@ -37,7 +37,7 @@ class HTMLTableColElement MOZ_FINAL : public nsGenericHTMLElement
   {
     SetHTMLAttr(nsGkAtoms::align, aAlign, aError);
   }
-  void GetCh(nsString& aCh)
+  void GetCh(DOMString& aCh)
   {
     GetHTMLAttr(nsGkAtoms::_char, aCh);
   }
@@ -45,7 +45,7 @@ class HTMLTableColElement MOZ_FINAL : public nsGenericHTMLElement
   {
     SetHTMLAttr(nsGkAtoms::_char, aCh, aError);
   }
-  void GetChOff(nsString& aChOff)
+  void GetChOff(DOMString& aChOff)
   {
     GetHTMLAttr(nsGkAtoms::charoff, aChOff);
   }
@@ -53,7 +53,7 @@ class HTMLTableColElement MOZ_FINAL : public nsGenericHTMLElement
   {
     SetHTMLAttr(nsGkAtoms::charoff, aChOff, aError);
   }
-  void GetVAlign(nsString& aVAlign)
+  void GetVAlign(DOMString& aVAlign)
   {
     GetHTMLAttr(nsGkAtoms::valign, aVAlign);
   }
@@ -61,7 +61,7 @@ class HTMLTableColElement MOZ_FINAL : public nsGenericHTMLElement
   {
     SetHTMLAttr(nsGkAtoms::valign, aVAlign, aError);
   }
-  void GetWidth(nsString& aWidth)
+  void GetWidth(DOMString& aWidth)
   {
     GetHTMLAttr(nsGkAtoms::width, aWidth);
   }
diff --git a/dom/html/HTMLTableElement.h b/dom/html/HTMLTableElement.h
index 049c4a91f67692..a2ca60c8abe554 100644
--- a/dom/html/HTMLTableElement.h
+++ b/dom/html/HTMLTableElement.h
@@ -96,7 +96,7 @@ class HTMLTableElement MOZ_FINAL : public nsGenericHTMLElement,
                                                    ErrorResult& aError);
   void DeleteRow(int32_t aIndex, ErrorResult& aError);
 
-  void GetAlign(nsString& aAlign)
+  void GetAlign(DOMString& aAlign)
   {
     GetHTMLAttr(nsGkAtoms::align, aAlign);
   }
@@ -104,7 +104,7 @@ class HTMLTableElement MOZ_FINAL : public nsGenericHTMLElement,
   {
     SetHTMLAttr(nsGkAtoms::align, aAlign, aError);
   }
-  void GetBorder(nsString& aBorder)
+  void GetBorder(DOMString& aBorder)
   {
     GetHTMLAttr(nsGkAtoms::border, aBorder);
   }
@@ -112,7 +112,7 @@ class HTMLTableElement MOZ_FINAL : public nsGenericHTMLElement,
   {
     SetHTMLAttr(nsGkAtoms::border, aBorder, aError);
   }
-  void GetFrame(nsString& aFrame)
+  void GetFrame(DOMString& aFrame)
   {
     GetHTMLAttr(nsGkAtoms::frame, aFrame);
   }
@@ -120,7 +120,7 @@ class HTMLTableElement MOZ_FINAL : public nsGenericHTMLElement,
   {
     SetHTMLAttr(nsGkAtoms::frame, aFrame, aError);
   }
-  void GetRules(nsString& aRules)
+  void GetRules(DOMString& aRules)
   {
     GetHTMLAttr(nsGkAtoms::rules, aRules);
   }
@@ -132,11 +132,15 @@ class HTMLTableElement MOZ_FINAL : public nsGenericHTMLElement,
   {
     GetHTMLAttr(nsGkAtoms::summary, aSummary);
   }
+  void GetSummary(DOMString& aSummary)
+  {
+    GetHTMLAttr(nsGkAtoms::summary, aSummary);
+  }
   void SetSummary(const nsAString& aSummary, ErrorResult& aError)
   {
     SetHTMLAttr(nsGkAtoms::summary, aSummary, aError);
   }
-  void GetWidth(nsString& aWidth)
+  void GetWidth(DOMString& aWidth)
   {
     GetHTMLAttr(nsGkAtoms::width, aWidth);
   }
@@ -144,7 +148,7 @@ class HTMLTableElement MOZ_FINAL : public nsGenericHTMLElement,
   {
     SetHTMLAttr(nsGkAtoms::width, aWidth, aError);
   }
-  void GetBgColor(nsString& aBgColor)
+  void GetBgColor(DOMString& aBgColor)
   {
     GetHTMLAttr(nsGkAtoms::bgcolor, aBgColor);
   }
@@ -152,7 +156,7 @@ class HTMLTableElement MOZ_FINAL : public nsGenericHTMLElement,
   {
     SetHTMLAttr(nsGkAtoms::bgcolor, aBgColor, aError);
   }
-  void GetCellPadding(nsString& aCellPadding)
+  void GetCellPadding(DOMString& aCellPadding)
   {
     GetHTMLAttr(nsGkAtoms::cellpadding, aCellPadding);
   }
@@ -160,7 +164,7 @@ class HTMLTableElement MOZ_FINAL : public nsGenericHTMLElement,
   {
     SetHTMLAttr(nsGkAtoms::cellpadding, aCellPadding, aError);
   }
-  void GetCellSpacing(nsString& aCellSpacing)
+  void GetCellSpacing(DOMString& aCellSpacing)
   {
     GetHTMLAttr(nsGkAtoms::cellspacing, aCellSpacing);
   }
diff --git a/dom/html/HTMLTableRowElement.h b/dom/html/HTMLTableRowElement.h
index 9afb506f87796f..a7cfd79a22ab33 100644
--- a/dom/html/HTMLTableRowElement.h
+++ b/dom/html/HTMLTableRowElement.h
@@ -37,7 +37,7 @@ class HTMLTableRowElement MOZ_FINAL : public nsGenericHTMLElement
     InsertCell(int32_t aIndex, ErrorResult& aError);
   void DeleteCell(int32_t aValue, ErrorResult& aError);
 
-  void GetAlign(nsString& aAlign)
+  void GetAlign(DOMString& aAlign)
   {
     GetHTMLAttr(nsGkAtoms::align, aAlign);
   }
@@ -45,7 +45,7 @@ class HTMLTableRowElement MOZ_FINAL : public nsGenericHTMLElement
   {
     SetHTMLAttr(nsGkAtoms::align, aAlign, aError);
   }
-  void GetCh(nsString& aCh)
+  void GetCh(DOMString& aCh)
   {
     GetHTMLAttr(nsGkAtoms::_char, aCh);
   }
@@ -53,7 +53,7 @@ class HTMLTableRowElement MOZ_FINAL : public nsGenericHTMLElement
   {
     SetHTMLAttr(nsGkAtoms::_char, aCh, aError);
   }
-  void GetChOff(nsString& aChOff)
+  void GetChOff(DOMString& aChOff)
   {
     GetHTMLAttr(nsGkAtoms::charoff, aChOff);
   }
@@ -61,7 +61,7 @@ class HTMLTableRowElement MOZ_FINAL : public nsGenericHTMLElement
   {
     SetHTMLAttr(nsGkAtoms::charoff, aChOff, aError);
   }
-  void GetVAlign(nsString& aVAlign)
+  void GetVAlign(DOMString& aVAlign)
   {
     GetHTMLAttr(nsGkAtoms::valign, aVAlign);
   }
@@ -69,7 +69,7 @@ class HTMLTableRowElement MOZ_FINAL : public nsGenericHTMLElement
   {
     SetHTMLAttr(nsGkAtoms::valign, aVAlign, aError);
   }
-  void GetBgColor(nsString& aBgColor)
+  void GetBgColor(DOMString& aBgColor)
   {
     GetHTMLAttr(nsGkAtoms::bgcolor, aBgColor);
   }
diff --git a/dom/html/HTMLTableSectionElement.h b/dom/html/HTMLTableSectionElement.h
index 02c557a6e015c7..b3f935679a7045 100644
--- a/dom/html/HTMLTableSectionElement.h
+++ b/dom/html/HTMLTableSectionElement.h
@@ -29,7 +29,7 @@ class HTMLTableSectionElement MOZ_FINAL : public nsGenericHTMLElement
     InsertRow(int32_t aIndex, ErrorResult& aError);
   void DeleteRow(int32_t aValue, ErrorResult& aError);
 
-  void GetAlign(nsString& aAlign)
+  void GetAlign(DOMString& aAlign)
   {
     GetHTMLAttr(nsGkAtoms::align, aAlign);
   }
@@ -37,7 +37,7 @@ class HTMLTableSectionElement MOZ_FINAL : public nsGenericHTMLElement
   {
     SetHTMLAttr(nsGkAtoms::align, aAlign, aError);
   }
-  void GetCh(nsString& aCh)
+  void GetCh(DOMString& aCh)
   {
     GetHTMLAttr(nsGkAtoms::_char, aCh);
   }
@@ -45,7 +45,7 @@ class HTMLTableSectionElement MOZ_FINAL : public nsGenericHTMLElement
   {
     SetHTMLAttr(nsGkAtoms::_char, aCh, aError);
   }
-  void GetChOff(nsString& aChOff)
+  void GetChOff(DOMString& aChOff)
   {
     GetHTMLAttr(nsGkAtoms::charoff, aChOff);
   }
@@ -53,7 +53,7 @@ class HTMLTableSectionElement MOZ_FINAL : public nsGenericHTMLElement
   {
     SetHTMLAttr(nsGkAtoms::charoff, aChOff, aError);
   }
-  void GetVAlign(nsString& aVAlign)
+  void GetVAlign(DOMString& aVAlign)
   {
     GetHTMLAttr(nsGkAtoms::valign, aVAlign);
   }
diff --git a/dom/html/HTMLTimeElement.cpp b/dom/html/HTMLTimeElement.cpp
index bb9367047c3de6..ea19d5c5eceac3 100644
--- a/dom/html/HTMLTimeElement.cpp
+++ b/dom/html/HTMLTimeElement.cpp
@@ -32,7 +32,7 @@ HTMLTimeElement::WrapNode(JSContext* cx)
 }
 
 void
-HTMLTimeElement::GetItemValueText(nsAString& text)
+HTMLTimeElement::GetItemValueText(DOMString& text)
 {
   if (HasAttr(kNameSpaceID_None, nsGkAtoms::datetime)) {
     GetDateTime(text);
diff --git a/dom/html/HTMLTimeElement.h b/dom/html/HTMLTimeElement.h
index b4cb69924899cb..3dad438a09e568 100644
--- a/dom/html/HTMLTimeElement.h
+++ b/dom/html/HTMLTimeElement.h
@@ -21,7 +21,7 @@ class HTMLTimeElement MOZ_FINAL : public nsGenericHTMLElement
   virtual ~HTMLTimeElement();
 
   // HTMLTimeElement WebIDL
-  void GetDateTime(nsAString& aDateTime)
+  void GetDateTime(DOMString& aDateTime)
   {
     GetHTMLAttr(nsGkAtoms::datetime, aDateTime);
   }
@@ -31,7 +31,7 @@ class HTMLTimeElement MOZ_FINAL : public nsGenericHTMLElement
     SetHTMLAttr(nsGkAtoms::datetime, aDateTime, aError);
   }
 
-  virtual void GetItemValueText(nsAString& text) MOZ_OVERRIDE;
+  virtual void GetItemValueText(DOMString& text) MOZ_OVERRIDE;
   virtual void SetItemValueText(const nsAString& text) MOZ_OVERRIDE;
   virtual nsresult Clone(mozilla::dom::NodeInfo* aNodeInfo, nsINode** aResult) const MOZ_OVERRIDE;
 
diff --git a/dom/html/HTMLTrackElement.h b/dom/html/HTMLTrackElement.h
index b0cdde8d7ef7ca..7db9a318bc2454 100644
--- a/dom/html/HTMLTrackElement.h
+++ b/dom/html/HTMLTrackElement.h
@@ -93,11 +93,9 @@ class HTMLTrackElement MOZ_FINAL : public nsGenericHTMLElement
   virtual nsresult Clone(mozilla::dom::NodeInfo* aNodeInfo, nsINode** aResult) const MOZ_OVERRIDE;
 
   // For Track, ItemValue reflects the src attribute
-  virtual void GetItemValueText(nsAString& aText) MOZ_OVERRIDE
+  virtual void GetItemValueText(DOMString& aText) MOZ_OVERRIDE
   {
-    DOMString value;
-    GetSrc(value);
-    value.ToString(aText);
+    GetSrc(aText);
   }
   virtual void SetItemValueText(const nsAString& aText) MOZ_OVERRIDE
   {
diff --git a/dom/html/nsGenericHTMLElement.cpp b/dom/html/nsGenericHTMLElement.cpp
index 1fab50ab830353..5b06127321120e 100644
--- a/dom/html/nsGenericHTMLElement.cpp
+++ b/dom/html/nsGenericHTMLElement.cpp
@@ -3034,7 +3034,7 @@ nsGenericHTMLElement::GetItemValue(JSContext* aCx, JSObject* aScope,
     return;
   }
 
-  nsString string;
+  DOMString string;
   GetItemValueText(string);
   if (!xpc::NonVoidStringToJsval(aCx, string, aRetval)) {
     aError.Throw(NS_ERROR_FAILURE);
@@ -3055,9 +3055,11 @@ nsGenericHTMLElement::GetItemValue(nsIVariant** aValue)
   if (ItemScope()) {
     out->SetAsISupports(static_cast<nsIContent*>(this));
   } else {
-    nsAutoString string;
+    DOMString string;
     GetItemValueText(string);
-    out->SetAsAString(string);
+    nsString xpcomString;
+    string.ToString(xpcomString);
+    out->SetAsAString(xpcomString);
   }
 
   out.forget(aValue);
@@ -3098,7 +3100,7 @@ nsGenericHTMLElement::SetItemValue(nsIVariant* aValue)
 }
 
 void
-nsGenericHTMLElement::GetItemValueText(nsAString& text)
+nsGenericHTMLElement::GetItemValueText(DOMString& text)
 {
   ErrorResult rv;
   GetTextContentInternal(text, rv);
diff --git a/dom/html/nsGenericHTMLElement.h b/dom/html/nsGenericHTMLElement.h
index 942c775519a3e6..6af7beeafe932a 100644
--- a/dom/html/nsGenericHTMLElement.h
+++ b/dom/html/nsGenericHTMLElement.h
@@ -68,7 +68,7 @@ class nsGenericHTMLElement : public nsGenericHTMLElementBase,
   // From Element
   nsresult CopyInnerTo(mozilla::dom::Element* aDest);
 
-  void GetTitle(nsString& aTitle)
+  void GetTitle(mozilla::dom::DOMString& aTitle)
   {
     GetHTMLAttr(nsGkAtoms::title, aTitle);
   }
@@ -77,7 +77,7 @@ class nsGenericHTMLElement : public nsGenericHTMLElementBase,
     SetHTMLAttr(nsGkAtoms::title, aTitle);
     return NS_OK;
   }
-  void GetLang(nsString& aLang)
+  void GetLang(mozilla::dom::DOMString& aLang)
   {
     GetHTMLAttr(nsGkAtoms::lang, aLang);
   }
@@ -86,7 +86,7 @@ class nsGenericHTMLElement : public nsGenericHTMLElementBase,
     SetHTMLAttr(nsGkAtoms::lang, aLang);
     return NS_OK;
   }
-  void GetDir(nsString& aDir)
+  void GetDir(mozilla::dom::DOMString& aDir)
   {
     GetHTMLEnumAttr(nsGkAtoms::dir, aDir);
   }
@@ -296,7 +296,7 @@ class nsGenericHTMLElement : public nsGenericHTMLElementBase,
 
   // These methods are used to implement element-specific behavior of Get/SetItemValue
   // when an element has @itemprop but no @itemscope.
-  virtual void GetItemValueText(nsAString& text);
+  virtual void GetItemValueText(mozilla::dom::DOMString& text);
   virtual void SetItemValueText(const nsAString& text);
 public:
   virtual already_AddRefed<mozilla::dom::UndoManager> GetUndoManager() MOZ_OVERRIDE;
@@ -318,21 +318,21 @@ class nsGenericHTMLElement : public nsGenericHTMLElementBase,
   NS_FORWARD_NSIDOMELEMENT_TO_GENERIC
 
   NS_IMETHOD GetTitle(nsAString& aTitle) MOZ_FINAL MOZ_OVERRIDE {
-    nsString title;
+    mozilla::dom::DOMString title;
     GetTitle(title);
-    aTitle.Assign(title);
+    title.ToString(aTitle);
     return NS_OK;
   }
   NS_IMETHOD GetLang(nsAString& aLang) MOZ_FINAL MOZ_OVERRIDE {
-    nsString lang;
+    mozilla::dom::DOMString lang;
     GetLang(lang);
-    aLang.Assign(lang);
+    lang.ToString(aLang);
     return NS_OK;
   }
   NS_IMETHOD GetDir(nsAString& aDir) MOZ_FINAL MOZ_OVERRIDE {
-    nsString dir;
+    mozilla::dom::DOMString dir;
     GetDir(dir);
-    aDir.Assign(dir);
+    dir.ToString(aDir);
     return NS_OK;
   }
   NS_IMETHOD SetDir(const nsAString& aDir) MOZ_FINAL MOZ_OVERRIDE {