Find Favicon in priority of icon_type.

chrome/browser/history/history_service.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_HISTORY_HISTORY_SERVICE_H_
 #define CHROME_BROWSER_HISTORY_HISTORY_SERVICE_H_
 
 #include <set>
 #include <vector>
 
@@ skipping 689 matching lines @@
   // only a single type will be returned in the priority of
   // TOUCH_PRECOMPOSED_ICON, TOUCH_ICON, and FAVICON.
   CancelableTaskTracker::TaskId GetFaviconsForURL(
       const GURL& page_url,
       int icon_types,
       int desired_size_in_dip,
       const std::vector<ui::ScaleFactor>& desired_scale_factors,
       const FaviconService::FaviconResultsCallback& callback,
       CancelableTaskTracker* tracker);
 
+  // Used by the FaviconService to get largest icon of |page_url| in the order

[sky, 2013/10/16 13:27:16]

Used by FaviconService to find the first icon whose width and height are greater
than or equal to that of |minimum_size_in_pixels|. This searches for icons by
IconType. Each element of |icon_types| is a bitmask of IconTypes indicating the
types to search for.

I don't see you doing this part of your comment: "If none icon is larger than
|minimal_size_in_pixel|, the largest one of all icon types in |icon_types| is
returned." Am I missing something?

[michaelbai, 2013/10/16 18:17:05]

In the HistoryBackend::GetLargestFaviconForURL, the largest icon is stored in
largest_icon local variable and this will always be returned no matter its size.

+  // of icon types given by |icon_types|.
+  // if the largest icon of first icon types given by |icon_types| is not
+  // larger than |minimal_size_in_pixel|, the next icon types of
+  // |params.icon_types| will be searched and so on.
+  // If none icon is larger than |minimal_size_in_pixel|, the largest
+  // one of all icon types in |icon_types| is returned.
+  // This feature is especially useful when some types of icon is perfered as
+  // long as its size is larger than a specific value.
+  CancelableTaskTracker::TaskId GetLargestFaviconForURL(
+      const GURL& page_url,
+      const std::vector<int>& icon_types,
+      int minimal_size_in_pixels,
+      const FaviconService::FaviconResultsCallback& callback,
+      CancelableTaskTracker* tracker);
+
   // Used by the FaviconService to get the favicon bitmap which most closely
   // matches |desired_size_in_dip| and |desired_scale_factor| from the favicon
   // with |favicon_id| from the history backend. If |desired_size_in_dip| is 0,
   // the largest favicon bitmap for |favicon_id| is returned.
   CancelableTaskTracker::TaskId GetFaviconForID(
       chrome::FaviconID favicon_id,
       int desired_size_in_dip,
       ui::ScaleFactor desired_scale_factor,
       const FaviconService::FaviconResultsCallback& callback,
       CancelableTaskTracker* tracker);
@@ skipping 343 matching lines @@
   scoped_ptr<history::InMemoryURLIndex> in_memory_url_index_;
 
   ObserverList<history::VisitDatabaseObserver> visit_database_observers_;
 
   history::DeleteDirectiveHandler delete_directive_handler_;
 
   DISALLOW_COPY_AND_ASSIGN(HistoryService);
 };
 
 #endif  // CHROME_BROWSER_HISTORY_HISTORY_SERVICE_H_