Cleanup GpuMemoryBuffer

content/common/gpu/client/command_buffer_proxy_impl.h

Index: content/common/gpu/client/command_buffer_proxy_impl.h
diff --git a/content/common/gpu/client/command_buffer_proxy_impl.h b/content/common/gpu/client/command_buffer_proxy_impl.h
index ea3974029cd1f820de57afbd8895504bed5ed174..13a11acc85db5c0a9b0af284fa07e2aee82ea587 100644
--- a/content/common/gpu/client/command_buffer_proxy_impl.h
+++ b/content/common/gpu/client/command_buffer_proxy_impl.h
@@ -150,12 +150,50 @@ class CommandBufferProxyImpl
     return shared_state_shm_->handle();
   }
 
+  void WaitForPendingGpuMemoryBufferUsageToComplete(
+      const base::Closure& callback);
+
  private:
   typedef std::map<int32, scoped_refptr<gpu::Buffer> > TransferBufferMap;
   typedef base::hash_map<uint32, base::Closure> SignalTaskMap;
   typedef base::ScopedPtrHashMap<int32, gfx::GpuMemoryBuffer>
       GpuMemoryBufferMap;
 
+  struct CallbackMessageLoopPair {
+    CallbackMessageLoopPair(const base::Closure& callback,
+                            scoped_refptr<base::MessageLoopProxy> message_loop);
+    ~CallbackMessageLoopPair();
+    base::Closure callback;
+    scoped_refptr<base::MessageLoopProxy> message_loop;

[reveman, 2014/10/23 19:46:43]

I just realized that GpuChannelHost::MessageFilter already handle routing of IPC
messages from the IO thread to the correct proxy thread. Could we remove the
routing here and instead use that? All
Proxy::WaitForPendingGpuMemoryBufferUsageToComplete calls would be guaranteed to
happen on the same thread as other calls.

+  };
+
+  class GpuMemoryBufferUsageTracker
+      : public base::RefCountedThreadSafe<GpuMemoryBufferUsageTracker>,
+        public DeletionObserver {
+   public:
+    GpuMemoryBufferUsageTracker();
+
+    // DeletionObserver implementation:
+    void OnWillDeleteImpl() override;
+
+    uint32 AddUsage(const CallbackMessageLoopPair& task);
+    void UsageCompleted(uint32 task_id);
+
+   private:
+    typedef base::hash_map<uint32, CallbackMessageLoopPair>
+        GpuMemoryBufferUsageCompletedMap;
+    friend class base::RefCountedThreadSafe<GpuMemoryBufferUsageTracker>;
+    ~GpuMemoryBufferUsageTracker();
+
+    void UsageCompletedOnCaller(uint32 task_id);
+
+    uint32 next_gpu_memory_buffer_usage_id_;
+    GpuMemoryBufferUsageCompletedMap gpu_memory_buffer_tasks_;
+    mutable base::Lock gpu_memory_buffer_task_lock_;
+  };
+
+  void WaitForPendingGpuMemoryBufferUsageToCompleteOnMain(uint32 usage_id);
+
   // Send an IPC message over the GPU channel. This is private to fully
   // encapsulate the channel; all callers of this function must explicitly
   // verify that the context has not been lost.
@@ -210,6 +248,9 @@ class CommandBufferProxyImpl
 
   SwapBuffersCompletionCallback swap_buffers_completion_callback_;
 
+  scoped_refptr<base::MessageLoopProxy> main_loop_proxy_;
+  scoped_refptr<GpuMemoryBufferUsageTracker> tracker_;
+
   DISALLOW_COPY_AND_ASSIGN(CommandBufferProxyImpl);
 };