[Sync] Replace uses of ObserverListThreadSafe with WeakHandles

chrome/browser/sync/test/engine/syncer_command_test.h

 // Copyright (c) 2011 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_SYNC_TEST_ENGINE_SYNCER_COMMAND_TEST_H_
 #define CHROME_BROWSER_SYNC_TEST_ENGINE_SYNCER_COMMAND_TEST_H_
 #pragma once
 
 #include <algorithm>
 #include <string>
 #include <vector>
 
 #include "base/compiler_specific.h"
+#include "base/message_loop.h"
 #include "chrome/browser/sync/engine/model_safe_worker.h"
 #include "chrome/browser/sync/sessions/debug_info_getter.h"
 #include "chrome/browser/sync/sessions/sync_session.h"
 #include "chrome/browser/sync/sessions/sync_session_context.h"
 #include "chrome/browser/sync/test/engine/mock_connection_manager.h"
 #include "chrome/browser/sync/test/engine/test_directory_setter_upper.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/gmock/include/gmock/gmock.h"
 
 using ::testing::NiceMock;
@@ skipping 126 matching lines @@
 
   MockConnectionManager* mock_server() {
     return mock_server_.get();
   }
 
   MockDebugInfoGetter* mock_debug_info_getter() {
     return &mock_debug_info_getter_;
   }
 
  private:
+  MessageLoop message_loop_;
   scoped_ptr<TestDirectorySetterUpper> syncdb_;
   scoped_ptr<sessions::SyncSessionContext> context_;
   scoped_ptr<MockConnectionManager> mock_server_;
   scoped_ptr<sessions::SyncSession> session_;
   std::vector<scoped_refptr<ModelSafeWorker> > workers_;
   ModelSafeRoutingInfo routing_info_;
   NiceMock<MockDebugInfoGetter> mock_debug_info_getter_;
   DISALLOW_COPY_AND_ASSIGN(SyncerCommandTestWithParam);
 };
 
 class SyncerCommandTest : public SyncerCommandTestWithParam<void*> {};
 
 class MockDirectorySyncerCommandTest
     : public SyncerCommandTestWithParam<void*> {
  public:
   MockDirectorySyncerCommandTest()
       : SyncerCommandTestWithParam<void*>(
           SyncerCommandTestWithParam<void*>::USE_MOCK_DIRECTORY) {}
   MockDirectorySetterUpper::MockDirectory* mock_directory() {
     return static_cast<MockDirectorySetterUpper*>(syncdb())->directory();
   }
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_TEST_ENGINE_SYNCER_COMMAND_TEST_H_