Moves the notification icon out of the status area overflow.

chrome/browser/status_icons/status_icon.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_STATUS_ICONS_STATUS_ICON_H_
 #define CHROME_BROWSER_STATUS_ICONS_STATUS_ICON_H_
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/observer_list.h"
 #include "base/strings/string16.h"
 #include "chrome/browser/status_icons/status_icon_menu_model.h"
 
 namespace gfx {
 class ImageSkia;
 }
 
 class StatusIconObserver;
 
+#if defined(OS_WIN)
+class StatusIconWin;
+#endif  // defined(OS_WIN)
+
 class StatusIcon {
  public:
   StatusIcon();
   virtual ~StatusIcon();
 
   // Sets the image associated with this status icon.
   virtual void SetImage(const gfx::ImageSkia& image) = 0;
 
   // Sets the image associated with this status icon when pressed.
   virtual void SetPressedImage(const gfx::ImageSkia& image) = 0;
@@ skipping 19 matching lines @@
   // being called, otherwise, both left and right clicks will display the
   // context menu (if any).
   void AddObserver(StatusIconObserver* observer);
   void RemoveObserver(StatusIconObserver* observer);
 
   // Returns true if there are registered click observers.
   bool HasObservers() const;
 
   // Dispatches a click event to the observers.
   void DispatchClickEvent();
+
 #if defined(OS_WIN)
+  // Dispatches a balloon click event to the observers.
   void DispatchBalloonClickEvent();
+
+  // Available on Windows so clients can access Windows-specific functionality
+  // like the backing HWND.
+  StatusIconWin* AsStatusIconWin();

[sky, 2014/03/19 22:26:39]

This means the parent class knows about a UI specific implementation. In general
we don't want the base classes knowing about specific implementations. You need
to find another way to go about this.

[dewittj, 2014/03/20 19:31:08]

Perhaps atwilson can suggest a better way.  In earlier iterations of this code
I'd used a static_cast<StatusIconWin*>(status_icon) but it seemed safer to avoid
static casts and just return NULL in scenarios where it's unsafe.  The trivial
change is for this to return a bool, and use that to inform whether a
static_cast is accepatble but I doubt that would actually satisfy your concern.

[sky, 2014/03/20 20:59:38]

If you can't actually have your code take a StatusIconWin, then yes, a
static_cast is what you should do.

 #endif
 
  protected:
   // Invoked after a call to SetContextMenu() to let the platform-specific
   // subclass update the native context menu based on the new model. If NULL is
   // passed, subclass should destroy the native context menu.
   virtual void UpdatePlatformContextMenu(StatusIconMenuModel* model) = 0;
 
  private:
   ObserverList<StatusIconObserver> observers_;
 
   // Context menu, if any.
   scoped_ptr<StatusIconMenuModel> context_menu_contents_;
 
   DISALLOW_COPY_AND_ASSIGN(StatusIcon);
 };
 
 #endif  // CHROME_BROWSER_STATUS_ICONS_STATUS_ICON_H_