Render the tab close button as a vector-based icon.

chrome/browser/ui/views/tabs/media_indicator_button.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_UI_VIEWS_TABS_MEDIA_INDICATOR_BUTTON_H_
 #define CHROME_BROWSER_UI_VIEWS_TABS_MEDIA_INDICATOR_BUTTON_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "chrome/browser/ui/tabs/tab_utils.h"
 #include "ui/views/controls/button/image_button.h"
@@ skipping 22 matching lines @@
 
   explicit MediaIndicatorButton(Tab* parent_tab);
   ~MediaIndicatorButton() override;
 
   // Returns the current TabMediaState except, while the indicator image is
   // fading out, returns the prior TabMediaState.
   TabMediaState showing_media_state() const {
     return showing_media_state_;
   }
 
-  // Updates ImageButton images, starts fade animations, and
-  // activates/deactivates button functionality as appropriate.
+  // Calls ResetImages(), starts fade animations, and activates/deactivates
+  // button functionality as appropriate.
   void TransitionToMediaState(TabMediaState next_state);
 
   // Determines whether the MediaIndicatorButton will be clickable for toggling
   // muting.  This should be called whenever the active/inactive state of a tab
   // has changed.  Internally, TransitionToMediaState() and OnBoundsChanged()
   // calls this when the TabMediaState or the bounds have changed.
   void UpdateEnabledForMuteToggle();
 
+  // Called when the parent tab's button color changes.  Determines whether
+  // ResetImages() needs to be called.
+  void OnParentTabButtonColorChanged();
+
  protected:
   // views::View:
   const char* GetClassName() const override;
   View* GetTooltipHandlerForPoint(const gfx::Point& point) override;
   bool OnMousePressed(const ui::MouseEvent& event) override;
   bool OnMouseDragged(const ui::MouseEvent& event) override;
   void OnMouseEntered(const ui::MouseEvent& event) override;
   void OnMouseMoved(const ui::MouseEvent& event) override;
   void OnBoundsChanged(const gfx::Rect& previous_bounds) override;
   void OnPaint(gfx::Canvas* canvas) override;
 
   // views::ViewTargeterDelegate
   bool DoesIntersectRect(const View* target,
                          const gfx::Rect& rect) const override;
 
   // views::Button:
   void NotifyClick(const ui::Event& event) override;
 
   // views::CustomButton:
   bool IsTriggerableEvent(const ui::Event& event) override;
 
  private:
   class FadeAnimationDelegate;
 
   // Returns the tab (parent view) of this MediaIndicatorButton.
   Tab* GetTab() const;
 
+  // Resets the images to display on the button to reflect |state| and the
+  // parent tab's button color.  Should be called when either of these changes.
+  void ResetImages(TabMediaState state);
+
   Tab* const parent_tab_;
 
   TabMediaState media_state_;
 
   // Media indicator fade-in/out animation (i.e., only on show/hide, not a
   // continuous animation).
   scoped_ptr<gfx::AnimationDelegate> fade_animation_delegate_;
   scoped_ptr<gfx::Animation> fade_animation_;
   TabMediaState showing_media_state_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaIndicatorButton);
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_TABS_MEDIA_INDICATOR_BUTTON_H_