Misc cleanups in Drive code.

chrome/browser/google_apis/gdata_wapi_service.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_BROWSER_GOOGLE_APIS_GDATA_WAPI_SERVICE_H_
 #define CHROME_BROWSER_GOOGLE_APIS_GDATA_WAPI_SERVICE_H_
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
@@ skipping 121 matching lines @@
 
   // DriveServiceObserver Overrides
   virtual void OnProgressUpdate(
       const OperationProgressStatusList& list) OVERRIDE;
 
   net::URLRequestContextGetter* url_request_context_getter_;  // Not owned.
   scoped_ptr<OperationRunner> runner_;
   ObserverList<DriveServiceObserver> observers_;
   // Operation objects should hold a copy of this, rather than a const
   // reference, as they may outlive this object.
-  GDataWapiUrlGenerator url_generator_;
+  const GDataWapiUrlGenerator url_generator_;
   const std::string custom_user_agent_;
 
   DISALLOW_COPY_AND_ASSIGN(GDataWapiService);
 };
 
 }  // namespace google_apis
 
 #endif  // CHROME_BROWSER_GOOGLE_APIS_GDATA_WAPI_SERVICE_H_