WebUI tab strip: fix new tab button does not change color OnThemeChange

Bug: 1225079
Change-Id: I0cab1dd657a29d765dec19fd1754377d0e8e92aa
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2994870
Commit-Queue: Yuheng Huang <yuhengh@chromium.org>
Reviewed-by: Collin Baker <collinbaker@chromium.org>
Reviewed-by: Thomas Lukaszewicz <tluk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#897144}

chrome/browser/ui/views/frame/webui_tab_strip_container_view.cc

@@ -233,6 +233,29 @@ class WebUITabStripWebView : public views::WebView {
 BEGIN_METADATA(WebUITabStripWebView, views::WebView)
 END_METADATA
 
+class WebUINewTabButton : public ToolbarButton {
+ public:
+  METADATA_HEADER(WebUINewTabButton);
+  explicit WebUINewTabButton(PressedCallback pressed_callback)
+      : ToolbarButton(pressed_callback) {
+    SetTooltipText(l10n_util::GetStringUTF16(IDS_TOOLTIP_NEW_TAB));
+    const int button_height = GetLayoutConstant(TOOLBAR_BUTTON_HEIGHT);
+    SetPreferredSize(gfx::Size(button_height, button_height));
+    SetHorizontalAlignment(gfx::ALIGN_CENTER);
+  }
+
+  void OnThemeChanged() override {
+    ToolbarButton::OnThemeChanged();
+    const SkColor normal_color = GetThemeProvider()->GetColor(
+        ThemeProperties::COLOR_TOOLBAR_BUTTON_ICON);
+    SetImage(views::Button::STATE_NORMAL,
+             gfx::CreateVectorIcon(kNewTabToolbarButtonIcon, normal_color));
+  }
+};
+
+BEGIN_METADATA(WebUINewTabButton, ToolbarButton)
+END_METADATA
+
 }  // namespace
 
 // When enabled, closes the container for taps in either the web content
@@ -587,24 +610,11 @@ views::NativeViewHost* WebUITabStripContainerView::GetNativeViewHost() {
 
 std::unique_ptr<views::View> WebUITabStripContainerView::CreateNewTabButton() {
   DCHECK_EQ(nullptr, new_tab_button_);
-  auto new_tab_button = std::make_unique<ToolbarButton>(
+  auto new_tab_button = std::make_unique<WebUINewTabButton>(
       base::BindRepeating(&WebUITabStripContainerView::NewTabButtonPressed,
                           base::Unretained(this)));
-  new_tab_button->SetTooltipText(
-      l10n_util::GetStringUTF16(IDS_TOOLTIP_NEW_TAB));
-  const SkColor normal_color =
-      GetThemeProvider()->GetColor(ThemeProperties::COLOR_TOOLBAR_BUTTON_ICON);
-  new_tab_button->SetImage(
-      views::Button::STATE_NORMAL,
-      gfx::CreateVectorIcon(kNewTabToolbarButtonIcon, normal_color));
-
-  const int button_height = GetLayoutConstant(TOOLBAR_BUTTON_HEIGHT);
-  new_tab_button->SetPreferredSize(gfx::Size(button_height, button_height));
-  new_tab_button->SetHorizontalAlignment(gfx::ALIGN_CENTER);
-
   new_tab_button_ = new_tab_button.get();
   view_observations_.AddObservation(new_tab_button_);
-
   return new_tab_button;
 }