Allow the renderer process to map textures from one context into another.

gpu/command_buffer/common/constants.h

 // Copyright (c) 2011 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_COMMON_CONSTANTS_H_
 #define GPU_COMMAND_BUFFER_COMMON_CONSTANTS_H_
 
 #include "../common/types.h"
 
 namespace gpu {
@@ skipping 24 matching lines @@
     kGuilty,
 
     // This context definitely did not provoke the loss of context.
     kInnocent,
 
     // It is unknown whether this context provoked the loss of context.
     kUnknown
   };
 }
 
+namespace resource_type {
+  enum ResourceType {
+    kTexture
+  };
+}
+
 // Invalid shared memory Id, returned by RegisterSharedMemory in case of
 // failure.
 const int32 kInvalidSharedMemoryId = -1;
 
 // Common Command Buffer shared memory transfer buffer ID.
 const int32 kCommandBufferSharedMemoryId = 4;
 
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_COMMON_CONSTANTS_H_