ui/compositor: Provide its own 'in process' ContextProvider.

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 WEBKIT_COMMON_GPU_CONTEXT_PROVIDER_IN_PROCESS_H_
 #define WEBKIT_COMMON_GPU_CONTEXT_PROVIDER_IN_PROCESS_H_
 
 #include <string>
 
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/thread_checker.h"
-#include "webkit/common/gpu/context_provider_web_context.h"
-#include "webkit/common/gpu/webkit_gpu_export.h"
-
-namespace blink { class WebGraphicsContext3D; }
+#include "cc/output/context_provider.h"
+#include "skia/ext/refptr.h"
 
 namespace gpu_blink {
 class WebGraphicsContext3DInProcessCommandBufferImpl;
 }
 
-namespace webkit {
-namespace gpu {
-class GrContextForWebGraphicsContext3D;
+namespace ui {
 
-class WEBKIT_GPU_EXPORT ContextProviderInProcess
-    : NON_EXPORTED_BASE(public ContextProviderWebContext) {
+class InProcessContextProvider : public cc::ContextProvider {
  public:
-  static scoped_refptr<ContextProviderInProcess> Create(
+  static scoped_refptr<InProcessContextProvider> Create(
       scoped_ptr<gpu_blink::WebGraphicsContext3DInProcessCommandBufferImpl>
           context3d,
       const std::string& debug_name);
 
   // Uses default attributes for creating an offscreen context.
-  static scoped_refptr<ContextProviderInProcess> CreateOffscreen(
+  static scoped_refptr<InProcessContextProvider> CreateOffscreen(
       bool lose_context_when_out_of_memory);
 
  private:
-  ContextProviderInProcess(
+  InProcessContextProvider(
       scoped_ptr<gpu_blink::WebGraphicsContext3DInProcessCommandBufferImpl>
           context3d,
       const std::string& debug_name);
-  ~ContextProviderInProcess() override;
-
-  // ContextProviderWebContext:
-  blink::WebGraphicsContext3D* WebContext3D() override;
+  ~InProcessContextProvider() override;
 
   // cc::ContextProvider:
   bool BindToCurrentThread() override;
   Capabilities ContextCapabilities() override;
   ::gpu::gles2::GLES2Interface* ContextGL() override;
   ::gpu::ContextSupport* ContextSupport() override;
   class GrContext* GrContext() override;
   bool IsContextLost() override;
   void VerifyContexts() override;
   void DeleteCachedResources() override;
   bool DestroyedOnMainThread() override;
   void SetLostContextCallback(
       const LostContextCallback& lost_context_callback) override;
   void SetMemoryPolicyChangedCallback(
       const MemoryPolicyChangedCallback& memory_policy_changed_callback)
       override;
 
   void OnLostContext();
   void InitializeCapabilities();
 
   base::ThreadChecker main_thread_checker_;
   base::ThreadChecker context_thread_checker_;
 
   scoped_ptr<gpu_blink::WebGraphicsContext3DInProcessCommandBufferImpl>
       context3d_;

[piman, 2015/01/21 02:07:36]

The gr_context_ change is a step in the right direction.
What I meant is that instead of having InProcessContextProvider own a
WebGraphicsContext3DInProcessCommandBufferImpl, which in turns owns a
GLInProcessContext, we could simply have InProcessContextProvider own the
GLInProcessContext, without an intermediate class.

You would have InProcessContextProvider::Create take an AcceleratedWidget
instead of the WebGraphicsContext3DInProcessCommandBufferImpl.
BindToCurrentThread would internally create the GLInProcessContext directly.
ContextGL() and ContextSupport() would directly return the
GLInProcessContext::GetImplementation()

You probably won't need the LostContextCallbackProxy any more, you could set the
LostContextCallback directly on the GLInProcessContext.

-  scoped_ptr<GrContextForWebGraphicsContext3D> gr_context_;
+  skia::RefPtr<class GrContext> gr_context_;
 
   LostContextCallback lost_context_callback_;
 
   base::Lock destroyed_lock_;
   bool destroyed_;
 
   std::string debug_name_;
   class LostContextCallbackProxy;
   scoped_ptr<LostContextCallbackProxy> lost_context_callback_proxy_;
 
   cc::ContextProvider::Capabilities capabilities_;
 
-  DISALLOW_COPY_AND_ASSIGN(ContextProviderInProcess);
+  DISALLOW_COPY_AND_ASSIGN(InProcessContextProvider);
 };
 
-}  // namespace gpu
-}  // namespace webkit
+}  // namespace ui
 
 #endif  // WEBKIT_COMMON_GPU_CONTEXT_PROVIDER_IN_PROCESS_H_