Update from https://crrev.com/311076

gpu/command_buffer/service/context_group.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_SERVICE_CONTEXT_GROUP_H_
 #define GPU_COMMAND_BUFFER_SERVICE_CONTEXT_GROUP_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 159 matching lines @@
   void LoseContexts(GLenum reset_status);
 
   // EXT_draw_buffer related states for backbuffer.
   GLenum draw_buffer() const {
     return draw_buffer_;
   }
   void set_draw_buffer(GLenum buf) {
     draw_buffer_ = buf;
   }
 
+  void AddBufferId(GLuint client_id, GLuint service_id) {
+    buffers_id_map_[client_id] = service_id;
+  }
+
+  bool GetBufferServiceId(GLuint client_id, GLuint* service_id) const {
+    std::map<GLuint, GLuint>::const_iterator iter =
+        buffers_id_map_.find(client_id);
+    if (iter == buffers_id_map_.end())
+      return false;
+    if (service_id)
+      *service_id = iter->second;
+    return true;
+  }
+
+  void RemoveBufferId(GLuint client_id) {
+    buffers_id_map_.erase(client_id);
+  }
+
   void AddSamplerId(GLuint client_id, GLuint service_id) {
     samplers_id_map_[client_id] = service_id;
   }
 
   bool GetSamplerServiceId(GLuint client_id, GLuint* service_id) const {
     std::map<GLuint, GLuint>::const_iterator iter =
         samplers_id_map_.find(client_id);
     if (iter == samplers_id_map_.end())
       return false;
     if (service_id)
@@ skipping 68 matching lines @@
 
   scoped_ptr<ShaderManager> shader_manager_;
 
   scoped_ptr<ValuebufferManager> valuebuffer_manager_;
 
   scoped_refptr<FeatureInfo> feature_info_;
 
   std::vector<base::WeakPtr<gles2::GLES2Decoder> > decoders_;
 
   // Mappings from client side IDs to service side IDs.
+  std::map<GLuint, GLuint> buffers_id_map_;
   std::map<GLuint, GLuint> samplers_id_map_;
   std::map<GLuint, GLuint> transformfeedbacks_id_map_;
 
   GLenum draw_buffer_;
 
   DISALLOW_COPY_AND_ASSIGN(ContextGroup);
 };
 
 }  // namespace gles2
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_SERVICE_CONTEXT_GROUP_H_