sync: avoid creating a HistoryModelWorker unless it is needed.

chrome/browser/sync/profile_sync_service_password_unittest.cc

 // Copyright (c) 2010 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 <vector>
 
 #include "testing/gtest/include/gtest/gtest.h"
 
 #include "base/task.h"
 #include "base/time.h"
@@ skipping 148 matching lines @@
       EXPECT_CALL(factory_, CreateDataTypeManager(_, _)).
           WillOnce(ReturnNewDataTypeManager());
 
       // We need tokens to get the tests going
       token_service_.IssueAuthTokenForTest(
           GaiaConstants::kSyncService, "token");
 
       EXPECT_CALL(profile_, GetTokenService()).
           WillRepeatedly(Return(&token_service_));
 
-      // Creating model safe workers will request the history service and
-      // password store.  I couldn't manage to convince gmock that splitting up
-      // the expectations to match the class responsibilities was a good thing,
-      // so we set them all together here.
-      EXPECT_CALL(profile_, GetHistoryService(_)).
-         WillOnce(Return(static_cast<HistoryService*>(NULL)));
-
       EXPECT_CALL(profile_, GetPasswordStore(_)).
           Times(2).
           WillRepeatedly(Return(password_store_.get()));
 
       EXPECT_CALL(observer_,
           Observe(
               NotificationType(NotificationType::SYNC_CONFIGURE_DONE),_,_));
 
       service_->RegisterDataTypeController(data_type_controller);
       service_->Initialize();
@@ skipping 348 matching lines @@
   AddPasswordEntriesTask node_task(this, sync_forms);
 
   StartSyncService(&root_task, &node_task);
 
   std::vector<PasswordForm> new_sync_forms;
   GetPasswordEntriesFromSyncDB(&new_sync_forms);
 
   EXPECT_EQ(1U, new_sync_forms.size());
   EXPECT_TRUE(ComparePasswords(expected_forms[0], new_sync_forms[0]));
 }