content: Cleanup class/struct forward declarations

content/public/common/content_client.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 CONTENT_PUBLIC_COMMON_CONTENT_CLIENT_H_
 #define CONTENT_PUBLIC_COMMON_CONTENT_CLIENT_H_
 
 #include <set>
 #include <string>
 #include <vector>
@@ skipping 20 matching lines @@
 }
 
 namespace gpu {
 struct GPUInfo;
 }
 
 namespace media {
 class MediaClientAndroid;
 }
 
-namespace sandbox {
-class TargetPolicy;
-}
-
 namespace content {
 
 class ContentBrowserClient;
 class ContentClient;
 class ContentGpuClient;
 class ContentRendererClient;
 class ContentUtilityClient;
 class OriginTrialPolicy;
 struct CdmInfo;
 struct PepperPluginInfo;
@@ skipping 138 matching lines @@
   ContentGpuClient* gpu_;
   // The embedder API for participating in renderer logic.
   ContentRendererClient* renderer_;
   // The embedder API for participating in utility logic.
   ContentUtilityClient* utility_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_COMMON_CONTENT_CLIENT_H_