Make FaviconService::GetRawFaviconForPageURL() select the best candidate among all the icon types

components/favicon/core/favicon_service.h

 // Copyright (c) 2017 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 COMPONENTS_FAVICON_CORE_FAVICON_SERVICE_H_
 #define COMPONENTS_FAVICON_CORE_FAVICON_SERVICE_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 70 matching lines @@
   // supported by the platform (e.g. MacOS). If data is unavailable for some or
   // all of the scale factors, the bitmaps with the best matching sizes are
   // resized.
   virtual base::CancelableTaskTracker::TaskId GetFaviconImageForPageURL(
       const GURL& page_url,
       const favicon_base::FaviconImageCallback& callback,
       base::CancelableTaskTracker* tracker) = 0;
 
   // Requests the favicon for the page at |page_url| with one of |icon_types|
   // and with |desired_size_in_pixel|. |icon_types| can be any combination of
-  // IconTypes. If favicon bitmaps for several IconTypes are available, the
-  // favicon bitmap is chosen in the priority of TOUCH_PRECOMPOSED_ICON,
-  // TOUCH_ICON and FAVICON. If there is no favicon bitmap of size
-  // |desired_size_in_pixel|, the favicon bitmap which best matches
-  // |desired_size_in_pixel| is resized. If |desired_size_in_pixel| is 0,
-  // the largest favicon bitmap is returned. Results with a higher priority
-  // IconType are preferred over an exact match of the favicon bitmap size.
+  // IconTypes. If there is no favicon bitmap of size |desired_size_in_pixel|,
+  // the favicon bitmap which best matches |desired_size_in_pixel| is resized.
+  // If |desired_size_in_pixel| is 0, the largest favicon bitmap is returned.
   virtual base::CancelableTaskTracker::TaskId GetRawFaviconForPageURL(
       const GURL& page_url,
       int icon_types,
       int desired_size_in_pixel,
       const favicon_base::FaviconRawBitmapCallback& callback,
       base::CancelableTaskTracker* tracker) = 0;
 
   // See HistoryService::GetLargestFaviconForPageURL().
   virtual base::CancelableTaskTracker::TaskId GetLargestRawFaviconForPageURL(
       const GURL& page_url,
@@ skipping 83 matching lines @@
 
   // Avoid repeated requests to download missing favicon.
   virtual void UnableToDownloadFavicon(const GURL& icon_url) = 0;
   virtual bool WasUnableToDownloadFavicon(const GURL& icon_url) const = 0;
   virtual void ClearUnableToDownloadFavicons() = 0;
 };
 
 }  // namespace favicon
 
 #endif  // COMPONENTS_FAVICON_CORE_FAVICON_SERVICE_H_