Change browser/page action default icon defined in manifest to support hidpi.

chrome/browser/ui/cocoa/extensions/browser_action_button.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_COCOA_EXTENSIONS_BROWSER_ACTION_BUTTON_H_
 #define CHROME_BROWSER_UI_COCOA_EXTENSIONS_BROWSER_ACTION_BUTTON_H_
 
 #import <Cocoa/Cocoa.h>
 
 #import "base/memory/scoped_nsobject.h"
 #include "base/memory/scoped_ptr.h"
 #import "chrome/browser/ui/cocoa/image_button_cell.h"
 
 class Browser;
 class ExtensionAction;
-class ExtensionImageTrackerBridge;
+class ExtensionActionIconFactoryBridge;
 
 namespace extensions {
 class Extension;
 }
 
 // Fired on each drag event while the user is moving the button.
 extern NSString* const kBrowserActionButtonDraggingNotification;
 // Fired when the user drops the button.
 extern NSString* const kBrowserActionButtonDragEndNotification;
 
 @interface BrowserActionButton : NSButton {
  @private
   // Bridge to proxy Chrome notifications to the Obj-C class as well as load the
   // extension's icon.
-  scoped_ptr<ExtensionImageTrackerBridge> imageLoadingBridge_;
+  scoped_ptr<ExtensionActionIconFactoryBridge> iconFactoryBridge_;
 
   // Used to move the button and query whether a button is currently animating.
   scoped_nsobject<NSViewAnimation> moveAnimation_;
 
   // The extension for this button. Weak.
   const extensions::Extension* extension_;
 
   // The ID of the active tab.
   int tabId_;
 
@@ skipping 35 matching lines @@
   // The action we're drawing the cell for. Weak.
   ExtensionAction* extensionAction_;
 }
 
 @property(readwrite, nonatomic) int tabId;
 @property(readwrite, nonatomic) ExtensionAction* extensionAction;
 
 @end
 
 #endif  // CHROME_BROWSER_UI_COCOA_EXTENSIONS_BROWSER_ACTION_BUTTON_H_