Add AsyncFlush when transferbuffer is > a certain size

gpu/command_buffer/client/transfer_buffer.h

Index: gpu/command_buffer/client/transfer_buffer.h
diff --git a/gpu/command_buffer/client/transfer_buffer.h b/gpu/command_buffer/client/transfer_buffer.h
index 654465c0cea6c9e125600dbf18a0431c86ef7541..b3a58d2d3e372bef66dd256ed9dd9d0e6780d0bb 100644
--- a/gpu/command_buffer/client/transfer_buffer.h
+++ b/gpu/command_buffer/client/transfer_buffer.h
@@ -60,7 +60,8 @@ class TransferBufferInterface {
       unsigned int result_size,
       unsigned int min_buffer_size,
       unsigned int max_buffer_size,
-      unsigned int alignment) = 0;
+      unsigned int alignment,
+      unsigned int size_to_flush) = 0;
 
   virtual int GetShmId() = 0;
   virtual void* GetResultBuffer() = 0;
@@ -94,7 +95,8 @@ class TransferBuffer : public TransferBufferInterface {
       unsigned int result_size,
       unsigned int min_buffer_size,
       unsigned int max_buffer_size,
-      unsigned int alignment) OVERRIDE;
+      unsigned int alignment,
+      unsigned int size_to_flush) OVERRIDE;
   virtual int GetShmId() OVERRIDE;
   virtual void* GetResultBuffer() OVERRIDE;
   virtual int GetResultOffset() OVERRIDE;
@@ -131,6 +133,12 @@ class TransferBuffer : public TransferBufferInterface {
   // alignment for allocations
   unsigned int alignment_;
 
+  // Size at which to do an async flush. 0 = never.
+  unsigned int size_to_flush_;
+
+  // Number of bytes since we last flushed.
+  unsigned int bytes_since_last_flush_;
+
   // the current buffer.
   gpu::Buffer buffer_;