Extend HistoryService with support for favicons from Google servers

components/history/core/browser/history_service.cc

 // 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.
 
 // The history system runs on a background thread so that potentially slow
 // database operations don't delay the browser. This backend processing is
 // represented by HistoryBackend. The HistoryService's job is to dispatch to
 // that thread.
 //
 // Main thread                       History thread
@@ skipping 607 matching lines @@
   DCHECK(backend_task_runner_) << "History service being called after cleanup";
   DCHECK(thread_checker_.CalledOnValidThread());
   if (history_client_ && !history_client_->CanAddURL(page_url))
     return;
 
   ScheduleTask(PRIORITY_NORMAL,
                base::Bind(&HistoryBackend::SetFavicons, history_backend_,
                           page_url, icon_type, icon_url, bitmaps));
 }
 
+void HistoryService::SetExpiredFaviconsIfNoneKnown(

[brettw, 2017/03/20 21:37:31]

This name is hard to make sense of without understanding the details of this
change. How about "SetLastResortFavicons"? Then the whole behavior of setting
the expired bit can be an implementation detail of how a "last resort" favicon
is defined.

+    const GURL& page_url,
+    favicon_base::IconType icon_type,
+    const GURL& icon_url,
+    const std::vector<SkBitmap>& bitmaps,
+    base::Callback<void(bool)> callback) {
+  DCHECK(backend_task_runner_) << "History service being called after cleanup";
+  DCHECK(thread_checker_.CalledOnValidThread());
+  if (history_client_ && !history_client_->CanAddURL(page_url))
+    return;
+
+  PostTaskAndReplyWithResult(
+      FROM_HERE,
+      base::Bind(&HistoryBackend::SetExpiredFaviconsIfNoneKnown,
+                 history_backend_, page_url, icon_type, icon_url, bitmaps),
+      callback);
+}
+
 void HistoryService::SetFaviconsOutOfDateForPage(const GURL& page_url) {
   DCHECK(backend_task_runner_) << "History service being called after cleanup";
   DCHECK(thread_checker_.CalledOnValidThread());
   ScheduleTask(PRIORITY_NORMAL,
                base::Bind(&HistoryBackend::SetFaviconsOutOfDateForPage,
                           history_backend_, page_url));
 }
 
 void HistoryService::SetImportedFavicons(
     const favicon_base::FaviconUsageDataList& favicon_usage) {
@@ skipping 511 matching lines @@
   return favicon_changed_callback_list_.Add(callback);
 }
 
 void HistoryService::NotifyFaviconsChanged(const std::set<GURL>& page_urls,
                                            const GURL& icon_url) {
   DCHECK(thread_checker_.CalledOnValidThread());
   favicon_changed_callback_list_.Notify(page_urls, icon_url);
 }
 
 }  // namespace history