gpu: Reuse transfer buffers more aggresively

gpu/command_buffer/client/gles2_implementation.h

 // Copyright (c) 2012 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_CLIENT_GLES2_IMPLEMENTATION_H_
 #define GPU_COMMAND_BUFFER_CLIENT_GLES2_IMPLEMENTATION_H_
 
 #include <GLES2/gl2.h>
 
 #include <map>
@@ skipping 573 matching lines @@
 
   // Asserts that the context is lost.
   // NOTE: This is an expensive call and should only be called
   // for error checking.
   bool MustBeContextLost();
 
   void RunIfContextNotLost(const base::Closure& callback);
 
   void OnSwapBuffersComplete();
 
+  // Free transfer buffer if unused token already passed, or free pending
+  // the unused token if not.
+  void FreeTransferBuffer(BufferTracker::Buffer* buffer);
+
+  // Insert async token. In the GLES2 command buffer, is implemented to
+  // enumerate and synchronize asynchronous pixel uploads.
+  void InsertAsyncPixelUnpackToken(BufferTracker::Buffer *buffer);
+
+  void MarkPixelTransferBufferLastUsage(BufferTracker::Buffer* buffer);
+
   bool GetBoundPixelTransferBuffer(
       GLenum target, const char* function_name, GLuint* buffer_id);
   BufferTracker::Buffer* GetBoundPixelUnpackTransferBufferIfValid(
       GLuint buffer_id,
       const char* function_name, GLuint offset, GLsizei size);
 
   const std::string& GetLogPrefix() const;
 
 #if defined(GL_CLIENT_FAIL_GL_ERRORS)
   void CheckGLError();
@@ skipping 150 matching lines @@
 
 inline bool GLES2Implementation::GetTexParameterivHelper(
     GLenum /* target */, GLenum /* pname */, GLint* /* params */) {
   return false;
 }
 
 }  // namespace gles2
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_CLIENT_GLES2_IMPLEMENTATION_H_