Add asserts to TestingProfile::CreateHistoryService to ensure files are deleted

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 "base/files/scoped_temp_dir.h"
@@ skipping 114 matching lines @@
   virtual ~TestingProfile();
 
   // 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.
-  void CreateHistoryService(bool delete_file, bool no_db);
+  // for testing error conditions. Returns true on success.
+  bool CreateHistoryService(bool delete_file, bool no_db) WARN_UNUSED_RESULT;
 
   // Shuts down and nulls out the reference to HistoryService.
   void DestroyHistoryService();
 
   // Creates TopSites. This returns immediately, and top sites may not be
   // loaded. Use BlockUntilTopSitesLoaded to ensure TopSites has finished
   // loading.
   void CreateTopSites();
 
   // Shuts down and nulls out the reference to TopSites.
@@ skipping 204 matching lines @@
 
   scoped_ptr<content::MockResourceContext> resource_context_;
 
   scoped_ptr<policy::ProfilePolicyConnector> profile_policy_connector_;
 
   // Weak pointer to a delegate for indicating that a profile was created.
   Delegate* delegate_;
 };
 
 #endif  // CHROME_TEST_BASE_TESTING_PROFILE_H_