Supporting high dpi favicons in Instant Extended.

chrome/renderer/searchbox/searchbox.h

Index: chrome/renderer/searchbox/searchbox.h
diff --git a/chrome/renderer/searchbox/searchbox.h b/chrome/renderer/searchbox/searchbox.h
index 38a766e02dbed0358093af43617a3b951cef1c42..4273d595b39087500e0d1cb0550911467de505c3 100644
--- a/chrome/renderer/searchbox/searchbox.h
+++ b/chrome/renderer/searchbox/searchbox.h
@@ -131,11 +131,13 @@ class SearchBox : public content::RenderViewObserver,
 
   // 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;