Speed up fix for expando-loss conformance test.

third_party/WebKit/Source/modules/webgl/WebGLVertexArrayObject.h

 // 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.
 
 #ifndef WebGLVertexArrayObject_h
 #define WebGLVertexArrayObject_h
 
 #include "modules/webgl/WebGLVertexArrayObjectBase.h"
 
 namespace blink {
 
 class WebGLVertexArrayObject final : public WebGLVertexArrayObjectBase {
     DEFINE_WRAPPERTYPEINFO();
 public:
     static WebGLVertexArrayObject* create(WebGLRenderingContextBase*, VaoType);
 
 private:
     explicit WebGLVertexArrayObject(WebGLRenderingContextBase*, VaoType);
+
+    // For preserving the wrappers of WebGLBuffer objects latched in
+    // via vertexAttribPointer calls.
+    v8::Persistent<v8::Array> m_bufferWrappers;
 };
 
 } // namespace blink
 
 #endif // WebGLVertexArrayObject_h