gpu: Reuse transfer buffers more aggresively

gpu/command_buffer/service/async_pixel_transfer_manager.h

 // Copyright 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 GPU_COMMAND_BUFFER_SERVICE_ASYNC_PIXEL_TRANSFER_MANAGER_H_
 #define GPU_COMMAND_BUFFER_SERVICE_ASYNC_PIXEL_TRANSFER_MANAGER_H_
 
 #include <set>
 
 #include "base/basictypes.h"
@@ skipping 45 matching lines @@
  public:
   static AsyncPixelTransferManager* Create(gfx::GLContext* context);
 
   virtual ~AsyncPixelTransferManager();
 
   void Initialize(gles2::TextureManager* texture_manager);
 
   virtual void BindCompletedAsyncTransfers() = 0;
 
   // There's no guarantee that callback will run on the caller thread.
+  virtual void AsyncRunWhenCompleted(base::Callback<void()> callback) = 0;

[reveman, 2014/01/22 17:30:04]

Can you drop "When" from this somehow? "Async" prefix already indicate that this
will run asynchronously sometime in the future. Maybe
AsyncRunCompletionCallback()? Also s/base::Callback<void()>/base::Closure/

[epenner, 2014/01/23 02:26:12]

This is very similar to AsyncNotifyCompletion both in how it works and what it
does in this instance. Could merge this somehow? Some thoughts:
- Could we use some kind of token API rather than queries in the client and
ditch the queries?
- Could the queries just record the token in the client and ditch the service
side stuff?

Nit: use 'base::Closure'

+
+  // There's no guarantee that callback will run on the caller thread.
   virtual void AsyncNotifyCompletion(
       const AsyncMemoryParams& mem_params,
       AsyncPixelTransferCompletionObserver* observer) = 0;
 
   virtual uint32 GetTextureUploadCount() = 0;
   virtual base::TimeDelta GetTotalTextureUploadTime() = 0;
 
   // ProcessMorePendingTransfers() will be called at a good time
   // to process a small amount of pending transfer work while
   // NeedsProcessMorePendingTransfers() returns true. Implementations
@@ skipping 34 matching lines @@
   virtual AsyncPixelTransferDelegate* CreatePixelTransferDelegateImpl(
       gles2::TextureRef* ref,
       const AsyncTexImage2DParams& define_params) = 0;
 
   DISALLOW_COPY_AND_ASSIGN(AsyncPixelTransferManager);
 };
 
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_SERVICE_ASYNC_PIXEL_TRANSFER_MANAGER_H_