Remove setErrorMessageCallback from WebGraphicsContext3D.

gpu/blink/webgraphicscontext3d_impl.cc

 // 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.
 
 #include "gpu/blink/webgraphicscontext3d_impl.h"
 
 #include <stdint.h>
 
 #include "base/atomicops.h"
 #include "base/lazy_instance.h"
@@ skipping 12 matching lines @@
 #define GL_GLEXT_PROTOTYPES 1
 #endif
 #include "third_party/khronos/GLES2/gl2ext.h"
 
 namespace gpu_blink {
 
 WebGraphicsContext3DImpl::WebGraphicsContext3DImpl()
     : initialized_(false),
       initialize_failed_(false),
       context_lost_callback_(0),
-      error_message_callback_(0),
       gl_(NULL) {}
 
 WebGraphicsContext3DImpl::~WebGraphicsContext3DImpl() {
 
 }
 
-void WebGraphicsContext3DImpl::setErrorMessageCallback(
-    WebGraphicsContext3D::WebGraphicsErrorMessageCallback* cb) {
-  error_message_callback_ = cb;
-}
-
 void WebGraphicsContext3DImpl::setContextLostCallback(
     WebGraphicsContext3D::WebGraphicsContextLostCallback* cb) {
   context_lost_callback_ = cb;
 }
 
 }  // namespace gpu_blink