[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>
 
 #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.
+  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_