Use a layer transform for the waiting throbber

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

 // Copyright (c) 2012 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_TAB_H_
 #define CHROME_BROWSER_UI_VIEWS_TABS_TAB_H_
 
 #include <list>
 #include <string>
 
@@ skipping 142 matching lines @@
   static int GetImmersiveHeight();
 
  private:
   friend class TabTest;
   FRIEND_TEST_ALL_PREFIXES(TabTest, CloseButtonLayout);
 
   friend class TabStripTest;
   FRIEND_TEST_ALL_PREFIXES(TabStripTest, TabHitTestMaskWhenStacked);
   FRIEND_TEST_ALL_PREFIXES(TabStripTest, TabCloseButtonVisibilityWhenStacked);
 
+  class ThrobberView;
+
   // The animation object used to swap the favicon with the sad tab icon.
   class FaviconCrashAnimation;
   class TabCloseButton;
 
   // Contains a cached image and the values used to generate it.
   struct ImageCacheEntry {
     ImageCacheEntry();
     ~ImageCacheEntry();
 
     // ID of the resource used.
@@ skipping 174 matching lines @@
   // Whole-tab throbbing "pulse" animation.
   scoped_ptr<gfx::ThrobAnimation> pulse_animation_;
 
   scoped_ptr<gfx::MultiAnimation> pinned_title_change_animation_;
 
   // Crash icon animation (in place of favicon).
   scoped_ptr<gfx::LinearAnimation> crash_icon_animation_;
 
   scoped_refptr<gfx::AnimationContainer> animation_container_;
 
-  views::View* throbber_;
+  ThrobberView* throbber_;
   MediaIndicatorButton* media_indicator_button_;
   views::ImageButton* close_button_;
   views::Label* title_;
 
   bool tab_activated_with_last_tap_down_;
 
   views::GlowHoverController hover_controller_;
 
   // The bounds of various sections of the display.
   gfx::Rect favicon_bounds_;
@@ skipping 28 matching lines @@
   SkColor button_color_;
 
   // As the majority of the tabs are inactive, and painting tabs is slowish,
   // we cache a handful of the inactive tab backgrounds here.
   static ImageCache* image_cache_;
 
   DISALLOW_COPY_AND_ASSIGN(Tab);
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_TABS_TAB_H_