Use mapped memory for uploading large textures.

gpu/command_buffer/client/ring_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.
 
 // This file contains the definition of the RingBuffer class.
 
 #ifndef GPU_COMMAND_BUFFER_CLIENT_RING_BUFFER_H_
 #define GPU_COMMAND_BUFFER_CLIENT_RING_BUFFER_H_
 
 #include <deque>
@@ skipping 36 matching lines @@
   void* Alloc(unsigned int size);
 
   // Frees a block of memory, pending the passage of a token. That memory won't
   // be re-allocated until the token has passed through the command stream.
   //
   // Parameters:
   //   pointer: the pointer to the memory block to free.
   //   token: the token value to wait for before re-using the memory.
   void FreePendingToken(void* pointer, unsigned int token);
 
+  // Discards a block within the ring buffer.
+  //
+  // Parameters:
+  //   pointer: the pointer to the memory block to free.
+  void DiscardBlock(void* pointer);
+
   // Gets the size of the largest free block that is available without waiting.
   unsigned int GetLargestFreeSizeNoWaiting();
 
   // Gets the size of the largest free block that can be allocated if the
   // caller can wait. Allocating a block of this size will succeed, but may
   // block.
   unsigned int GetLargestFreeOrPendingSize() {
     return size_;
   }
 
@@ skipping 61 matching lines @@
 
   // The physical address that corresponds to base_offset.
   void* base_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(RingBuffer);
 };
 
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_CLIENT_RING_BUFFER_H_