[Fallback Icons] Refactor FallbackIconService to be a BrowserContext-level singleton

chrome/test/base/testing_profile.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_TEST_BASE_TESTING_PROFILE_H_
 #define CHROME_TEST_BASE_TESTING_PROFILE_H_
 
 #include <string>
+#include <utility>
+#include <vector>

[Jay Civelli, 2015/03/26 05:14:56]

Do you need these includes?

[huangs, 2015/03/26 18:26:06]

I don't, but these were suggested by "git cl lint".

 
 #include "base/files/scoped_temp_dir.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "chrome/browser/profiles/profile.h"
 #include "components/domain_reliability/clear_mode.h"
 #include "components/keyed_service/content/browser_context_keyed_service_factory.h"
 
 namespace content {
 class MockResourceContext;
@@ skipping 138 matching lines @@
 #endif
                  scoped_ptr<PrefServiceSyncable> prefs,
                  TestingProfile* parent,
                  bool guest_session,
                  const std::string& supervised_user_id,
                  scoped_ptr<policy::PolicyService> policy_service,
                  const TestingFactories& factories);
 
   ~TestingProfile() override;
 
+  // Creates the fallback icon service. Consequent calls would recreate the
+  // service.

[Jay Civelli, 2015/03/26 05:14:56]

I am not sure I understand the "Consequent calls would recreate the
 service." Looking at the code it does not look like calling that again will
recreate anything.

[huangs, 2015/03/26 18:26:06]

The comment was copied from the line 173.  By "Looking at the code" you meant
digging into FaviconServiceFactory and see that BuildFallbackIconService() only
gets called once at most?

Removed "Consequent calls..." from new code.

+  void CreateFallbackIconService();
+
   // Creates the favicon service. Consequent calls would recreate the service.
   void CreateFaviconService();
 
   // Creates the history service. If |delete_file| is true, the history file is
   // deleted first, then the HistoryService is created. As TestingProfile
   // deletes the directory containing the files used by HistoryService, this
   // only matters if you're recreating the HistoryService.  If |no_db| is true,
   // the history backend will fail to initialize its database; this is useful
   // for testing error conditions. Returns true on success.
   bool CreateHistoryService(bool delete_file, bool no_db) WARN_UNUSED_RESULT;
@@ skipping 229 matching lines @@
 
   // Weak pointer to a delegate for indicating that a profile was created.
   Delegate* delegate_;
 
   std::string profile_name_;
 
   scoped_ptr<policy::PolicyService> policy_service_;
 };
 
 #endif  // CHROME_TEST_BASE_TESTING_PROFILE_H_