[Oilpan] Migrate classes under module/webgl onto oilpan heap

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"
-#include "wtf/PassRefPtr.h"
 
 namespace blink {
 
 class WebGLVertexArrayObject final : public WebGLVertexArrayObjectBase {
     DEFINE_WRAPPERTYPEINFO();
 public:
-    static PassRefPtrWillBeRawPtr<WebGLVertexArrayObject> create(WebGLRenderingContextBase*, VaoType);
+    static WebGLVertexArrayObject* create(WebGLRenderingContextBase*, VaoType);
 
 private:
     explicit WebGLVertexArrayObject(WebGLRenderingContextBase*, VaoType);
 };
 
 } // namespace blink
 
 #endif // WebGLVertexArrayObject_h