[Favicon] Add new fallback icon rendering flow.

chrome/browser/ui/webui/favicon_source.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_UI_WEBUI_FAVICON_SOURCE_H_
 #define CHROME_BROWSER_UI_WEBUI_FAVICON_SOURCE_H_
 
 #include <map>
 #include <string>
 
@@ skipping 23 matching lines @@
 //    Values: ['largest', size/aa@bx/]
 //    'largest': Specifies that the largest available favicon is requested.
 //      Example: chrome://favicon/largest/http://www.google.com/
 //    'size/aa@bx/':
 //      Specifies the requested favicon's size in DIP (aa) and the requested
 //      favicon's scale factor. (b).
 //      The supported requested DIP sizes are: 16x16, 32x32 and 64x64.
 //      If the parameter is unspecified, the requested favicon's size defaults
 //      to 16 and the requested scale factor defaults to 1x.
 //      Example: chrome://favicon/size/16@2x/http://www.google.com/
-//  'urlmodifier'      Optional
+//  'urlmodifier'       Optional
 //    Values: ['iconurl', 'origin']
 //    'iconurl': Specifies that the url parameter refers to the URL of
 //    the favicon image as opposed to the URL of the page that the favicon is
 //    on.
 //    Example: chrome://favicon/iconurl/http://www.google.com/favicon.ico
 //    'origin': Specifies that the URL should be converted to a form with
 //    an empty path and a valid scheme. The converted URL will be used to
 //    request the favicon from the favicon service.
 //    Examples:
 //      chrome://favicon/origin/http://example.com/a
@@ skipping 79 matching lines @@
   // database doesn't have a favicon for a webpage. Indexed by IconSize values.
   scoped_refptr<base::RefCountedMemory> default_favicons_[NUM_SIZES];
 
   // The favicon_base::IconTypes of icon that this FaviconSource handles.
   int icon_types_;
 
   DISALLOW_COPY_AND_ASSIGN(FaviconSource);
 };
 
 #endif  // CHROME_BROWSER_UI_WEBUI_FAVICON_SOURCE_H_