Reduce internal Flush() in GL resource glGen/Delete APIs.

gpu/command_buffer/client/cmd_buffer_helper.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.
 
 // This file contains the command buffer helper class.
 
 #ifndef GPU_COMMAND_BUFFER_CLIENT_CMD_BUFFER_HELPER_H_
 #define GPU_COMMAND_BUFFER_CLIENT_CMD_BUFFER_HELPER_H_
 
 #include <string.h>
@@ skipping 238 matching lines @@
   }
 
   CommandBuffer* command_buffer() const {
     return command_buffer_;
   }
 
   Buffer get_ring_buffer() const {
     return ring_buffer_;
   }
 
+  uint32 flush_generation() const { return flush_generation_; }
+
   void FreeRingBuffer();
 
   bool HaveRingBuffer() const {
     return ring_buffer_id_ != -1;
   }
 
   bool usable () const {
     return usable_;
   }
 
@@ skipping 35 matching lines @@
   int commands_issued_;
 #endif
 
   bool usable_;
   bool context_lost_;
   bool flush_automatically_;
 
   // Using C runtime instead of base because this file cannot depend on base.
   clock_t last_flush_time_;
 
+  // Incremented every time the helper flushes the command buffer.
+  // Can be used to track when prior commands have been flushed.
+  uint32 flush_generation_;
+
   friend class CommandBufferHelperTest;
   DISALLOW_COPY_AND_ASSIGN(CommandBufferHelper);
 };
 
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_CLIENT_CMD_BUFFER_HELPER_H_