Supporting high dpi favicons in Instant Extended.

chrome/renderer/searchbox/searchbox.h

 // Copyright 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_RENDERER_SEARCHBOX_SEARCHBOX_H_
 #define CHROME_RENDERER_SEARCHBOX_SEARCHBOX_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
@@ skipping 113 matching lines @@
   // |url|. If the |transient_url| is invalid, returns false  and |url| is not
   // set.
   //
   // Valid form of |transient_url|:
   //    chrome-search://thumb/<render_view_id>/<most_visited_item_id>
   bool GenerateThumbnailURLFromTransientURL(const GURL& transient_url,
                                             GURL* url) const;
 
   // Generates the favicon URL of the most visited item specified by the
   // |transient_url|. If the |transient_url| is valid, returns true and fills in
-  // |url|. If the |transient_url| is invalid, returns false  and |url| is not
-  // set.
+  // |url|. If the |transient_url| is invalid, returns true and |url| is set to
+  // "chrome-search://favicon/" in order to prevent the invalid URL to be
+  // requested.
   //
-  // Valid form of |transient_url|:
-  //    chrome-search://favicon/<render_view_id>/<most_visited_item_id>
+  // Valid forms of |transient_url|:
+  //    chrome-search://favicon/<view_id>/<restricted_id>
+  //    chrome-search://favicon/<favicon_parameters>/<view_id>/<restricted_id>
   bool GenerateFaviconURLFromTransientURL(const GURL& transient_url,
                                           GURL* url) const;
 
  private:
   // Overridden from content::RenderViewObserver:
   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
 
   void OnChange(const string16& query,
                 bool verbatim,
                 size_t selection_start,
@@ skipping 53 matching lines @@
   size_t omnibox_font_size_;
   bool app_launcher_enabled_;
   InstantRestrictedIDCache<InstantAutocompleteResult>
       autocomplete_results_cache_;
   InstantRestrictedIDCache<InstantMostVisitedItem> most_visited_items_cache_;
 
   DISALLOW_COPY_AND_ASSIGN(SearchBox);
 };
 
 #endif  // CHROME_RENDERER_SEARCHBOX_SEARCHBOX_H_