command_buffer: Support instanced path rendering in gpu command buffer

gpu/command_buffer/client/transfer_buffer.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_TRANSFER_BUFFER_H_
 #define GPU_COMMAND_BUFFER_CLIENT_TRANSFER_BUFFER_H_
 
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "gpu/command_buffer/client/ring_buffer.h"
@@ skipping 128 matching lines @@
       unsigned int size,
       CommandBufferHelper* helper,
       TransferBufferInterface* transfer_buffer)
       : buffer_(NULL),
         size_(0),
         helper_(helper),
         transfer_buffer_(transfer_buffer) {
     Reset(size);
   }
 
+  // Constructs an empty and invalid allocation that should be Reset() later.
+  ScopedTransferBufferPtr(CommandBufferHelper* helper,
+                          TransferBufferInterface* transfer_buffer)
+      : buffer_(NULL),
+        size_(0),
+        helper_(helper),
+        transfer_buffer_(transfer_buffer) {}
+
   ~ScopedTransferBufferPtr() {
     Release();
   }
 
   bool valid() const {
     return buffer_ != NULL;
   }
 
   unsigned int size() const {
     return size_;
@@ skipping 40 matching lines @@
   }
 
   unsigned int num_elements() const {
     return size() / sizeof(T);
   }
 };
 
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_CLIENT_TRANSFER_BUFFER_H_