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

chrome/browser/status_icons/status_icon.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_STATUS_ICONS_STATUS_ICON_H_
 #define CHROME_BROWSER_STATUS_ICONS_STATUS_ICON_H_
 #pragma once
 
 #include "base/memory/scoped_ptr.h"
 #include "base/observer_list.h"
@@ skipping 13 matching lines @@
   // Sets the image associated with this status icon.
   virtual void SetImage(const SkBitmap& image) = 0;
 
   // Sets the image associated with this status icon when pressed.
   virtual void SetPressedImage(const SkBitmap& image) = 0;
 
   // Sets the hover text for this status icon.
   virtual void SetToolTip(const string16& tool_tip) = 0;
 
   // Displays a notification balloon with the specified contents.
-  virtual void DisplayBalloon(const string16& title,
+  // Depending on the platform it might not appear by the icon tray.
+  virtual void DisplayBalloon(const SkBitmap& icon,
+                              const string16& title,
                               const string16& contents) = 0;
 
   // Set the context menu for this icon. The icon takes ownership of the passed
   // context menu. Passing NULL results in no menu at all.
   void SetContextMenu(ui::MenuModel* menu);
 
   class Observer {
    public:
     virtual ~Observer() {}
 
     // Called when the user clicks on the system tray icon. Clicks that result
     // in the context menu being displayed will not be passed to this observer
     // (i.e. if there's a context menu set on this status icon, and the user
     // right clicks on the icon to display the context menu, OnClicked will not
     // be called).
+    // Note: Chrome OS displays the context menu on left button clicks.
+    // This will only be fired for this platform if no context menu is present.
     virtual void OnClicked() = 0;
   };
 
   // Adds/Removes an observer for clicks on the status icon. If an observer is
   // registered, then left clicks on the status icon will result in the observer
   // being called, otherwise, both left and right clicks will display the
   // context menu (if any).
   void AddObserver(Observer* observer);
   void RemoveObserver(Observer* observer);
 
@@ skipping 10 matching lines @@
   virtual void UpdatePlatformContextMenu(ui::MenuModel* model) = 0;
 
  private:
   ObserverList<Observer> observers_;
   // Context menu, if any.
   scoped_ptr<ui::MenuModel> context_menu_contents_;
   DISALLOW_COPY_AND_ASSIGN(StatusIcon);
 };
 
 #endif  // CHROME_BROWSER_STATUS_ICONS_STATUS_ICON_H_