gpu: Reuse transfer buffers more aggresively

gpu/command_buffer/client/gles2_implementation.h

Index: gpu/command_buffer/client/gles2_implementation.h
diff --git a/gpu/command_buffer/client/gles2_implementation.h b/gpu/command_buffer/client/gles2_implementation.h
index 102bd66abc10a34e5d12223262fc56e59df6b4f0..ce27481a059ec7d0d39e7c8b734bae719a5c7743 100644
--- a/gpu/command_buffer/client/gles2_implementation.h
+++ b/gpu/command_buffer/client/gles2_implementation.h
@@ -591,6 +591,17 @@ class GLES2_IMPL_EXPORT GLES2Implementation
 
   void OnSwapBuffersComplete();
 
+  // Free transfer buffer if unused token already passed, or free pending
+  // the unused token if not.
+  void FreeTransferBuffer(BufferTracker::Buffer* buffer);
+
+  // Internal async upload query.
+  void BeginInternalQueryAsyncPixelUnpackCompleted(
+      BufferTracker::Buffer *buffer);
+  void EndInternalQueryAsyncPixelUnpackCompleted();
+
+  void MarkPixelTransferBufferLastUsage(BufferTracker::Buffer* buffer);
+
   bool GetBoundPixelTransferBuffer(
       GLenum target, const char* function_name, GLuint* buffer_id);
   BufferTracker::Buffer* GetBoundPixelUnpackTransferBufferIfValid(
@@ -698,7 +709,8 @@ class GLES2_IMPL_EXPORT GLES2Implementation
   scoped_refptr<ShareGroup> share_group_;
 
   scoped_ptr<QueryTracker> query_tracker_;
-  typedef std::map<GLuint, QueryTracker::Query*> QueryMap;
+  typedef std::pair<GLuint, bool> QueryKey;
+  typedef std::map<QueryKey, QueryTracker::Query*> QueryMap;
   QueryMap current_queries_;
 
   scoped_ptr<BufferTracker> buffer_tracker_;