Revert of cc: Use worker context for one-copy tile initialization.

ui/compositor/test/in_process_context_provider.h

 // Copyright (c) 2013 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_COMPOSITOR_TEST_IN_PROCESS_CONTEXT_PROVIDER_H_
 #define UI_COMPOSITOR_TEST_IN_PROCESS_CONTEXT_PROVIDER_H_
 
 #include <string>
 
 #include "base/macros.h"
@@ skipping 31 matching lines @@
   InProcessContextProvider(
       const gpu::gles2::ContextCreationAttribHelper& attribs,
       gpu::GpuMemoryBufferManager* gpu_memory_buffer_manager,
       gpu::ImageFactory* image_factory,
       gfx::AcceleratedWidget window,
       const std::string& debug_name);
   ~InProcessContextProvider() override;
 
   // cc::ContextProvider:
   bool BindToCurrentThread() override;
-  void DetachFromThread() override;
   Capabilities ContextCapabilities() override;
   gpu::gles2::GLES2Interface* ContextGL() override;
   gpu::ContextSupport* ContextSupport() override;
   class GrContext* GrContext() override;
   void InvalidateGrContext(uint32_t state) override;
   void SetupLock() override;
   base::Lock* GetLock() override;
   void VerifyContexts() override;
   void DeleteCachedResources() override;
   bool DestroyedOnMainThread() override;
@@ skipping 24 matching lines @@
   bool destroyed_;
 
   base::Lock context_lock_;
 
   DISALLOW_COPY_AND_ASSIGN(InProcessContextProvider);
 };
 
 }  // namespace ui
 
 #endif  // UI_COMPOSITOR_TEST_IN_PROCESS_CONTEXT_PROVIDER_H_