blimp: Cleanup class/struct forward declarations

blimp/client/public/blimp_client_context.h

 // Copyright 2016 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 BLIMP_CLIENT_PUBLIC_BLIMP_CLIENT_CONTEXT_H_
 #define BLIMP_CLIENT_PUBLIC_BLIMP_CLIENT_CONTEXT_H_
 
 #include <memory>
 #include <string>
 
 #include "base/memory/ref_counted.h"
 #include "base/single_thread_task_runner.h"
 #include "blimp/client/public/blimp_client_context_delegate.h"
 #include "blimp/client/public/contents/blimp_contents.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "components/prefs/command_line_pref_store.h"
 #include "components/prefs/pref_registry_simple.h"
 #include "components/prefs/pref_service.h"
 #include "ui/gfx/native_widget_types.h"
 
 #if defined(OS_ANDROID)
 #include "base/android/jni_android.h"
 #endif  // defined(OS_ANDROID)
 
-namespace base {
-class SupportsUserData;
-}
-
 namespace blimp {
 namespace client {
 class CompositorDependencies;
 
 // BlimpClientContext is the core class for the Blimp client. It provides hooks
 // for creating BlimpContents and other features that are per
 // BrowserContext/Profile.
 class BlimpClientContext : public KeyedService {
  public:
 #if defined(OS_ANDROID)
@@ skipping 44 matching lines @@
   BlimpClientContext() = default;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(BlimpClientContext);
 };
 
 }  // namespace client
 }  // namespace blimp
 
 #endif  // BLIMP_CLIENT_PUBLIC_BLIMP_CLIENT_CONTEXT_H_