cc: Implement shared worker contexts. (v1)

content/common/gpu/client/context_provider_command_buffer.h

Index: content/common/gpu/client/context_provider_command_buffer.h
diff --git a/content/common/gpu/client/context_provider_command_buffer.h b/content/common/gpu/client/context_provider_command_buffer.h
index 1e0d23f82b915609416ce8473e6d4f83d6fd24bb..2dd5ef5dc48749594d42bb92f7967ea43e587966 100644
--- a/content/common/gpu/client/context_provider_command_buffer.h
+++ b/content/common/gpu/client/context_provider_command_buffer.h
@@ -30,6 +30,11 @@ class CONTENT_EXPORT ContextProviderCommandBuffer
 
   CommandBufferProxyImpl* GetCommandBufferProxy();
 
+  // Destroy WebGraphicsContext3DCommandBufferImpl context and GrContext. This
+  // should only be used if content provider has been set up for multi-threaded
+  // usage by calling SetupLock().
+  void Destroy();
+
   // cc_blink::ContextProviderWebContext implementation.
   WebGraphicsContext3DCommandBufferImpl* WebContext3D() override;
 
@@ -45,12 +50,13 @@ class CONTENT_EXPORT ContextProviderCommandBuffer
   Capabilities ContextCapabilities() override;
   void VerifyContexts() override;
   void DeleteCachedResources() override;
-  bool DestroyedOnMainThread() override;
+  bool HasBeenLostOnMainThread() override;
   void SetLostContextCallback(
       const LostContextCallback& lost_context_callback) override;
   void SetMemoryPolicyChangedCallback(
       const MemoryPolicyChangedCallback& memory_policy_changed_callback)
       override;
+  bool HasBeenDestroyed() override;
 
  protected:
   ContextProviderCommandBuffer(
@@ -63,6 +69,7 @@ class CONTENT_EXPORT ContextProviderCommandBuffer
 
  private:
   void InitializeCapabilities();
+  void DestroyWithLockAcquired();
 
   base::ThreadChecker main_thread_checker_;
   base::ThreadChecker context_thread_checker_;
@@ -78,9 +85,10 @@ class CONTENT_EXPORT ContextProviderCommandBuffer
   MemoryPolicyChangedCallback memory_policy_changed_callback_;
 
   base::Lock main_thread_lock_;
-  bool destroyed_;
+  bool lost_;
 
   base::Lock context_lock_;
+  bool destroyed_;
 
   class LostContextCallbackProxy;
   scoped_ptr<LostContextCallbackProxy> lost_context_callback_proxy_;