Bug 825392 - Parent Touch objects to the EventTarget's global. r=bz

dom/events/Touch.cpp

@@ -8,6 +8,7 @@
 #include "mozilla/dom/EventTarget.h"
 #include "mozilla/dom/TouchBinding.h"
 #include "mozilla/dom/TouchEvent.h"
+#include "nsGlobalWindow.h"
 #include "nsContentUtils.h"
 #include "nsIContent.h"
 
@@ -139,5 +140,22 @@ Touch::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aScope)
   return TouchBinding::Wrap(aCx, aScope, this);
 }
 
+// Parent ourselves to the window of the target. This achieves the desirable
+// effects of parenting to the target, but avoids making the touch inaccessible
+// when the target happens to be NAC and therefore reflected into the XBL scope.
+EventTarget*
+Touch::GetParentObject()
+{
+  if (!mTarget) {
+    return nullptr;
+  }
+  nsCOMPtr<nsPIDOMWindow> outer = do_QueryInterface(mTarget->GetOwnerGlobal());
+  if (!outer) {
+    return nullptr;
+  }
+  MOZ_ASSERT(outer->IsOuterWindow());
+  return static_cast<nsGlobalWindow*>(outer->GetCurrentInnerWindow());
+}
+
 } // namespace dom
 } // namespace mozilla

dom/events/Touch.h

@@ -58,7 +58,8 @@ class Touch MOZ_FINAL : public nsISupports
 
   virtual JSObject* WrapObject(JSContext* aCx,
                                JS::Handle<JSObject*> aScope) MOZ_OVERRIDE;
-  EventTarget* GetParentObject() { return mTarget; }
+
+  EventTarget* GetParentObject();
 
   // WebIDL
   int32_t Identifier() const { return mIdentifier; }