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

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 178 matching lines @@
 
   // views::ContextMenuController:
   void ShowContextMenuForView(views::View* source,
                               const gfx::Point& point,
                               ui::MenuSourceType source_type) override;
 
   // views::MaskedTargeterDelegate:
   bool GetHitTestMask(gfx::Path* mask) const override;
 
   // views::View:
+  void ViewHierarchyChanged(
+      const ViewHierarchyChangedDetails& details) override;
   void OnPaint(gfx::Canvas* canvas) override;
   void Layout() override;
   void OnThemeChanged() override;
   const char* GetClassName() const override;
   bool GetTooltipText(const gfx::Point& p,
                       base::string16* tooltip) const override;
   bool GetTooltipTextOrigin(const gfx::Point& p,
                             gfx::Point* origin) const override;
   bool OnMousePressed(const ui::MouseEvent& event) override;
   bool OnMouseDragged(const ui::MouseEvent& event) override;
@@ skipping 63 matching lines @@
 
   void DisplayCrashedFavicon();
   void ResetCrashedFavicon();
 
   void StopCrashAnimation();
   void StartCrashAnimation();
 
   // Returns true if the crash animation is currently running.
   bool IsPerformingCrashAnimation() const;
 
+  // Calculates the correct |close_button_color_| and sets the close button
+  // normal-state image.  This should be called any time the theme or active
+  // state may have changed.
+  void SetCloseButtonNormalStateImage();
+
   // Schedules repaint task for icon.
   void ScheduleIconPaint();
 
   // Returns a |path| containing the region that matches the bitmap display of
   // this tab, for input event hit testing.  Set |include_top_shadow| to include
   // the mostly-transparent shadow pixels above the top edge of the tab in the
   // path.
   void GetHitTestMaskHelper(bool include_top_shadow, gfx::Path* path) const;
 
   // Returns the rectangle for the light bar in immersive mode.
@@ skipping 107 matching lines @@
   SkColor close_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_