Add an extra argument to the DisplayBalloon method to support custom notification icons.

chrome/browser/ui/cocoa/status_icons/status_icon_mac.h

 // Copyright (c) 2011 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_STATUS_ICONS_STATUS_ICON_MAC_H_
 #define CHROME_BROWSER_UI_COCOA_STATUS_ICONS_STATUS_ICON_MAC_H_
 #pragma once
 
 #import <Cocoa/Cocoa.h>
 
+#include "base/compiler_specific.h"
 #include "base/memory/scoped_nsobject.h"
 #include "base/string16.h"
 #include "chrome/browser/status_icons/status_icon.h"
 
 class SkBitmap;
 @class NSStatusItem;
 @class StatusItemController;
 
 class StatusIconMac : public StatusIcon {
  public:
   StatusIconMac();
   virtual ~StatusIconMac();
 
   // Overridden from StatusIcon
-  virtual void SetImage(const SkBitmap& image);
-  virtual void SetPressedImage(const SkBitmap& image);
-  virtual void SetToolTip(const string16& tool_tip);
-  virtual void DisplayBalloon(const string16& title, const string16& contents);
+  virtual void SetImage(const SkBitmap& image) OVERRIDE;
+  virtual void SetPressedImage(const SkBitmap& image) OVERRIDE;
+  virtual void SetToolTip(const string16& tool_tip) OVERRIDE;
+  virtual void DisplayBalloon(const SkBitmap& icon,
+                              const string16& title,
+                              const string16& contents) OVERRIDE;
 
  protected:
   // Overridden from StatusIcon.
   virtual void UpdatePlatformContextMenu(ui::MenuModel* menu);
 
  private:
   // Getter for item_ that allows lazy initialization.
   NSStatusItem* item();
   scoped_nsobject<NSStatusItem> item_;
 
   scoped_nsobject<StatusItemController> controller_;
 
   DISALLOW_COPY_AND_ASSIGN(StatusIconMac);
 };
 
-
 #endif // CHROME_BROWSER_UI_COCOA_STATUS_ICONS_STATUS_ICON_MAC_H_