No need to forward declare GeolocationProviderTest in geolocation_provider_impl.h.

content/browser/geolocation/geolocation_provider_impl.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_BROWSER_GEOLOCATION_GEOLOCATION_PROVIDER_IMPL_H_
 #define CONTENT_BROWSER_GEOLOCATION_GEOLOCATION_PROVIDER_IMPL_H_
 
 #include <list>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/callback_forward.h"
 #include "base/compiler_specific.h"
 #include "base/threading/thread.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/geolocation_provider.h"
 #include "content/public/common/geoposition.h"
 
 template<typename Type> struct DefaultSingletonTraits;
 
 namespace content {
 class GeolocationArbitrator;
-class GeolocationProviderTest;
 
 // This is the main API to the geolocation subsystem. The application will hold
 // a single instance of this class and can register multiple clients to be
 // notified of location changes:
 // * Callbacks are registered by AddLocationUpdateCallback() and will keep
 //   receiving updates until unregistered by RemoveLocationUpdateCallback().
 // The application must instantiate the GeolocationProvider on the IO thread and
 // must communicate with it on the same thread.
 // The underlying location arbitrator will only be enabled whilst there is at
 // least one registered observer or pending callback. The arbitrator and the
@@ skipping 71 matching lines @@
 
   // Only to be used on the geolocation thread.
   GeolocationArbitrator* arbitrator_;
 
   DISALLOW_COPY_AND_ASSIGN(GeolocationProviderImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_GEOLOCATION_GEOLOCATION_PROVIDER_IMPL_H_