[Sync] Replace uses of ObserverListThreadSafe with WeakHandles

chrome/browser/sync/sessions/sync_session_unittest.cc

 // 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.
 
 #include "chrome/browser/sync/sessions/sync_session.h"
 
 #include "base/compiler_specific.h"
 #include "base/location.h"
 #include "base/memory/ref_counted.h"
+#include "base/message_loop.h"
 #include "chrome/browser/sync/engine/conflict_resolver.h"
 #include "chrome/browser/sync/engine/mock_model_safe_workers.h"
 #include "chrome/browser/sync/engine/syncer_types.h"
 #include "chrome/browser/sync/syncable/directory_manager.h"
 #include "chrome/browser/sync/syncable/model_type.h"
 #include "chrome/browser/sync/syncable/syncable.h"
 #include "chrome/browser/sync/test/engine/test_directory_setter_upper.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using syncable::WriteTransaction;
@@ skipping 74 matching lines @@
     request_params[syncable::AUTOFILL] = true;
     return request_params;
   }
 
   syncable::ModelTypeBitSet ParamsMeaningJustOneEnabledType() {
     syncable::ModelTypeBitSet request_params;
     request_params[syncable::AUTOFILL] = true;
     return request_params;
   }
 
+  MessageLoop message_loop_;
   bool controller_invocations_allowed_;
   scoped_ptr<SyncSession> session_;
   scoped_ptr<SyncSessionContext> context_;
   ModelSafeRoutingInfo routes_;
 };
 
 TEST_F(SyncSessionTest, ScopedContextHelpers) {
   ConflictResolver resolver;
   EXPECT_FALSE(context_->resolver());
   {
@@ skipping 362 matching lines @@
   EXPECT_EQ(empty_payload, original[syncable::BOOKMARKS]);
   EXPECT_EQ(payload1, original[syncable::PASSWORDS]);
   EXPECT_EQ(payload1, original[syncable::AUTOFILL]);
   EXPECT_EQ(payload2, original[syncable::SESSIONS]);
   EXPECT_EQ(payload3, original[syncable::THEMES]);
 }
 
 }  // namespace
 }  // namespace sessions
 }  // namespace browser_sync