chrome: Cleanup class/struct forward declarations

chrome/service/cloud_print/cloud_print_proxy_backend.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_SERVICE_CLOUD_PRINT_CLOUD_PRINT_PROXY_BACKEND_H_
 #define CHROME_SERVICE_CLOUD_PRINT_CLOUD_PRINT_PROXY_BACKEND_H_
 
 #include <list>
 #include <string>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/single_thread_task_runner.h"
 #include "base/threading/thread.h"
 #include "chrome/service/cloud_print/connector_settings.h"
 #include "printing/backend/print_backend.h"
 
-namespace base {
-class DictionaryValue;
-}
-
 namespace gaia {
 struct OAuthClientInfo;
 }
 
 namespace cloud_print {
 
 // CloudPrintProxyFrontend is the interface used by CloudPrintProxyBackend to
 // communicate with the entity that created it and, presumably, is interested in
 // cloud print proxy related activity.
 // NOTE: All methods will be invoked by a CloudPrintProxyBackend on the same
@@ skipping 70 matching lines @@
   CloudPrintProxyFrontend* const frontend_;
 
   friend class base::RefCountedThreadSafe<CloudPrintProxyBackend::Core>;
 
   DISALLOW_COPY_AND_ASSIGN(CloudPrintProxyBackend);
 };
 
 }  // namespace cloud_print
 
 #endif  // CHROME_SERVICE_CLOUD_PRINT_CLOUD_PRINT_PROXY_BACKEND_H_