Use favicon for application shortcut icon.

chrome/browser/tab_contents/tab_contents.h

 // Copyright (c) 2009 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_TAB_CONTENTS_TAB_CONTENTS_H_
 #define CHROME_BROWSER_TAB_CONTENTS_TAB_CONTENTS_H_
 
 #include "build/build_config.h"
 
 #include <map>
@@ skipping 204 matching lines @@
   // bar. Normally this is true so you can see the URL. This is set to false
   // for the new tab page and related pages so that the URL bar is empty and
   // the user is invited to type into it.
   virtual bool ShouldDisplayURL();
 
   // Returns the favicon for this tab, or an isNull() bitmap if the tab does not
   // have a favicon. The default implementation uses the current navigation
   // entry.
   SkBitmap GetFavIcon() const;
 
+  // Returns true if we are not using the default favicon.
+  bool FavIconIsValid() const;
+
   // Returns whether the favicon should be displayed. If this returns false, no
   // space is provided for the favicon, and the favicon is never displayed.
   virtual bool ShouldDisplayFavIcon();
 
   // Returns a human-readable description the tab's loading state.
   virtual std::wstring GetStatusText() const;
 
   // Return whether this tab contents is loading a resource.
   bool is_loading() const { return is_loading_; }
 
@@ skipping 916 matching lines @@
   // If this tab was created from a renderer using window.open, this will be
   // non-NULL and represent the DOMUI of the opening renderer.
   DOMUITypeID opener_dom_ui_type_;
 
   // ---------------------------------------------------------------------------
 
   DISALLOW_COPY_AND_ASSIGN(TabContents);
 };
 
 #endif  // CHROME_BROWSER_TAB_CONTENTS_TAB_CONTENTS_H_