ui: Cleanup class/struct forward declarations

ui/android/context_provider_factory.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 UI_ANDROID_CONTEXT_PROVIDER_FACTORY_H_
 #define UI_ANDROID_CONTEXT_PROVIDER_FACTORY_H_
 
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "cc/surfaces/frame_sink_id.h"
 #include "ui/android/ui_android_export.h"
 
 namespace cc {
 class ContextProvider;
 class VulkanContextProvider;
-class SharedBitmapManager;
 class SurfaceManager;
 }
 
 namespace gpu {
 namespace gles2 {
 struct ContextCreationAttribHelper;
 }  // namespace gles
 
 struct SharedMemoryLimits;
 class GpuChannelHost;
@@ skipping 54 matching lines @@
   virtual cc::SurfaceManager* GetSurfaceManager() = 0;
 
   virtual cc::FrameSinkId AllocateFrameSinkId() = 0;
 
   virtual gpu::GpuMemoryBufferManager* GetGpuMemoryBufferManager() = 0;
 };
 
 }  // namespace ui
 
 #endif  // UI_ANDROID_CONTEXT_PROVIDER_FACTORY_H_