Use hi-resolution favicon variants if available.

chrome/common/icon_messages.h

Index: chrome/common/icon_messages.h
diff --git a/chrome/common/icon_messages.h b/chrome/common/icon_messages.h
index 5f04c94d2816508e044fcf839e29b533bf68a9c1..303af37ced10dd232a7fdb8463c29de7c3b007c4 100644
--- a/chrome/common/icon_messages.h
+++ b/chrome/common/icon_messages.h
@@ -27,9 +27,7 @@ IPC_STRUCT_TRAITS_END()
 IPC_MESSAGE_ROUTED3(IconMsg_DownloadFavicon,
                     int /* identifier for the request */,
                     GURL /* URL of the image */,
-                    int /* Size of the image. Normally 0, but set if you have
-                           a preferred image size to request, such as when
-                           downloading the favicon */)
+                    std::vector<int> /* XXX */)
 
 // Messages sent from the renderer to the browser.
 
@@ -42,4 +40,4 @@ IPC_MESSAGE_ROUTED4(IconHostMsg_DidDownloadFavicon,
                     int /* Identifier of the request */,
                     GURL /* URL of the image */,
                     bool /* true if there was a network error */,
-                    SkBitmap /* image_data */)
+                    std::vector<SkBitmap> /* image_data */)