Remove GetSharedMainThreadContextProvider from CompositorDependencies.

content/renderer/render_thread_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_RENDERER_RENDER_THREAD_IMPL_H_
 #define CONTENT_RENDERER_RENDER_THREAD_IMPL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 198 matching lines @@
   bool IsPartialRasterEnabled() override;
   bool IsGpuMemoryBufferCompositorResourcesEnabled() override;
   bool IsElasticOverscrollEnabled() override;
   std::vector<unsigned> GetImageTextureTargets() override;
   scoped_refptr<base::SingleThreadTaskRunner>
   GetCompositorMainThreadTaskRunner() override;
   scoped_refptr<base::SingleThreadTaskRunner>
   GetCompositorImplThreadTaskRunner() override;
   gpu::GpuMemoryBufferManager* GetGpuMemoryBufferManager() override;
   scheduler::RendererScheduler* GetRendererScheduler() override;
-  cc::ContextProvider* GetSharedMainThreadContextProvider() override;
   std::unique_ptr<cc::BeginFrameSource> CreateExternalBeginFrameSource(
       int routing_id) override;
   cc::ImageSerializationProcessor* GetImageSerializationProcessor() override;
   cc::TaskGraphRunner* GetTaskGraphRunner() override;
   bool AreImageDecodeTasksEnabled() override;
   bool IsThreadedAnimationEnabled() override;
 
   // Synchronously establish a channel to the GPU plugin if not previously
   // established or if it has been lost (for example if the GPU plugin crashed).
   // If there is a pending asynchronous request, it will be completed by the
@@ skipping 480 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(RenderThreadImpl);
 };
 
 #if defined(COMPILER_MSVC)
 #pragma warning(pop)
 #endif
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_RENDER_THREAD_IMPL_H_