Remove WebGLObject maps from WebGLRenderingContextBase and WebGLContextGroup.

third_party/WebKit/Source/modules/webgl/WebGLSync.cpp

 // Copyright 2015 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 "modules/webgl/WebGLSync.h"
 
 #include "gpu/command_buffer/client/gles2_interface.h"
 #include "modules/webgl/WebGL2RenderingContextBase.h"
 
 namespace blink {
 
-WebGLSync::~WebGLSync() {
-  // See the comment in WebGLObject::detachAndDeleteObject().
-  detachAndDeleteObject();
-}
-
 WebGLSync::WebGLSync(WebGL2RenderingContextBase* ctx,
                      GLsync object,
                      GLenum objectType)
     : WebGLSharedObject(ctx), m_object(object), m_objectType(objectType) {}
 
+WebGLSync::~WebGLSync() {
+  runDestructor();
+}
+
 void WebGLSync::deleteObjectImpl(gpu::gles2::GLES2Interface* gl) {
   gl->DeleteSync(m_object);
   m_object = 0;
 }
 
 }  // namespace blink