[Refactor] Simplify HistoryBackend::UpdateFaviconMappingsAndFetchImpl() signature

components/history/core/browser/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 COMPONENTS_HISTORY_CORE_BROWSER_HISTORY_SERVICE_H_
 #define COMPONENTS_HISTORY_CORE_BROWSER_HISTORY_SERVICE_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 626 matching lines @@
   // deleted. |url_id| is the id of the url row.
   void NotifyKeywordSearchTermDeleted(URLID url_id);
 
   // Favicon -------------------------------------------------------------------
 
   // These favicon methods are exposed to the FaviconService. Instead of calling
   // these methods directly you should call the respective method on the
   // FaviconService.
 
   // Used by FaviconService to get the favicon bitmaps from the history backend
-  // whose edge sizes most closely match |desired_sizes| for |icon_types|. If
+  // whose edge sizes most closely match |desired_sizes| for |icon_type|. If
   // |desired_sizes| has a '0' entry, the largest favicon bitmap for
-  // |icon_types| is returned. The returned FaviconBitmapResults will have at
+  // |icon_type| is returned. The returned FaviconBitmapResults will have at
   // most one result for each entry in |desired_sizes|. If a favicon bitmap is
   // determined to be the best candidate for multiple |desired_sizes| there will
   // be fewer results.
-  // If |icon_types| has several types, results for only a single type will be
-  // returned in the priority of TOUCH_PRECOMPOSED_ICON, TOUCH_ICON, and
-  // FAVICON.
-  base::CancelableTaskTracker::TaskId GetFavicons(
-      const std::vector<GURL>& icon_urls,
-      int icon_types,
+  base::CancelableTaskTracker::TaskId GetFavicon(
+      const GURL& icon_url,
+      favicon_base::IconType icon_type,
       const std::vector<int>& desired_sizes,
       const favicon_base::FaviconResultsCallback& callback,
       base::CancelableTaskTracker* tracker);
 
   // Used by the FaviconService to get favicons mapped to |page_url| for
   // |icon_types| whose edge sizes most closely match |desired_sizes|. If
   // |desired_sizes| has a '0' entry, the largest favicon bitmap for
   // |icon_types| is returned. The returned FaviconBitmapResults will have at
   // most one result for each entry in |desired_sizes|. If a favicon bitmap is
   // determined to be the best candidate for multiple |desired_sizes| there
@@ skipping 28 matching lines @@
   // Used by the FaviconService to get the favicon bitmap which most closely
   // matches |desired_size| from the favicon with |favicon_id| from the history
   // backend. If |desired_size| is 0, the largest favicon bitmap for
   // |favicon_id| is returned.
   base::CancelableTaskTracker::TaskId GetFaviconForID(
       favicon_base::FaviconID favicon_id,
       int desired_size,
       const favicon_base::FaviconResultsCallback& callback,
       base::CancelableTaskTracker* tracker);
 
-  // Used by the FaviconService to replace the favicon mappings to |page_url|
-  // for |icon_types| on the history backend.
-  // Sample |icon_urls|:
-  //  { ICON_URL1 -> TOUCH_ICON, known to the database,
-  //    ICON_URL2 -> TOUCH_ICON, not known to the database,
-  //    ICON_URL3 -> TOUCH_PRECOMPOSED_ICON, known to the database }
-  // The new mappings are computed from |icon_urls| with these rules:
-  // 1) Any urls in |icon_urls| which are not already known to the database are
-  //    rejected.
-  //    Sample new mappings to |page_url|: { ICON_URL1, ICON_URL3 }
-  // 2) If |icon_types| has multiple types, the mappings are only set for the
-  //    largest icon type.
-  //    Sample new mappings to |page_url|: { ICON_URL3 }
-  // |icon_types| can only have multiple IconTypes if
-  // |icon_types| == TOUCH_ICON | TOUCH_PRECOMPOSED_ICON.
-  // The favicon bitmaps whose edge sizes most closely match |desired_sizes|
-  // from the favicons which were just mapped to |page_url| are returned. If
-  // |desired_sizes| has a '0' entry, the largest favicon bitmap is returned.
+  // Maps |page_url| to the favicon at |icon_url| if there is an entry in the
+  // database for |icon_url| and |icon_type|. This occurs when there is a
+  // mapping from a different page URL to |icon_url|. The favicon bitmaps whose
+  // edge sizes most closely match |desired_sizes| from the favicons which were
+  // just mapped to |page_url| are returned. If |desired_sizes| has a '0' entry,
+  // the largest favicon bitmap is returned.
   base::CancelableTaskTracker::TaskId UpdateFaviconMappingsAndFetch(
       const GURL& page_url,
-      const std::vector<GURL>& icon_urls,
-      int icon_types,
+      const GURL& icon_url,
+      favicon_base::IconType icon_type,
       const std::vector<int>& desired_sizes,
       const favicon_base::FaviconResultsCallback& callback,
       base::CancelableTaskTracker* tracker);
 
   // Used by FaviconService to set a favicon for |page_url| and |icon_url| with
   // |pixel_size|.
   // Example:
   //   |page_url|: www.google.com
   // 2 favicons in history for |page_url|:
   //   www.google.com/a.ico  16x16
@@ skipping 117 matching lines @@
 
   // All vended weak pointers are invalidated in Cleanup().
   base::WeakPtrFactory<HistoryService> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(HistoryService);
 };
 
 }  // namespace history
 
 #endif  // COMPONENTS_HISTORY_CORE_BROWSER_HISTORY_SERVICE_H_