Add OVERRIDE to chrome/browser/extensions/.

chrome/browser/extensions/extension_icon_manager.h

Index: chrome/browser/extensions/extension_icon_manager.h
diff --git a/chrome/browser/extensions/extension_icon_manager.h b/chrome/browser/extensions/extension_icon_manager.h
index 6ce37a1faddec48aeff381984214c4b71cfc1e7b..a4a7813e49acbb09bdcc9b55b35e3e19728e4bce 100644
--- a/chrome/browser/extensions/extension_icon_manager.h
+++ b/chrome/browser/extensions/extension_icon_manager.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -35,7 +35,7 @@ class ExtensionIconManager : public ImageLoadingTracker::Observer {
 
   // Implements the ImageLoadingTracker::Observer interface.
   virtual void OnImageLoaded(SkBitmap* image, const ExtensionResource& resource,
-                             int index);
+                             int index) OVERRIDE;
 
   void set_monochrome(bool value) { monochrome_ = value; }
   void set_padding(const gfx::Insets& value) { padding_ = value; }