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

Source/modules/webgl/CHROMIUMValuebuffer.cpp

 // Copyright (c) 2014 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 "config.h"
 
 #include "modules/webgl/CHROMIUMValuebuffer.h"
 
 #include "modules/webgl/WebGLRenderingContextBase.h"
 
 namespace blink {
 
-CHROMIUMValuebuffer* CHROMIUMValuebuffer::create(WebGLRenderingContextBase* ctx)
+PassRefPtrWillBeRawPtr<CHROMIUMValuebuffer> CHROMIUMValuebuffer::create(WebGLRenderingContextBase* ctx)
 {
-    return new CHROMIUMValuebuffer(ctx);
+    return adoptRefWillBeNoop(new CHROMIUMValuebuffer(ctx));
 }
 
 CHROMIUMValuebuffer::~CHROMIUMValuebuffer()
 {
-    // See the comment in WebGLObject::detachAndDeleteObject().
+    // Always call detach here to ensure that platform object deletion
+    // happens with Oilpan enabled. It keeps the code regular to do it
+    // with or without Oilpan enabled.
+    //
+    // See comment in WebGLBuffer's destructor for additional
+    // information on why this is done for WebGLSharedObject-derived
+    // objects.
     detachAndDeleteObject();
 }
 
 CHROMIUMValuebuffer::CHROMIUMValuebuffer(WebGLRenderingContextBase* ctx)
     : WebGLSharedPlatform3DObject(ctx)
     , m_hasEverBeenBound(false)
 {
     setObject(ctx->webContext()->createValuebufferCHROMIUM());
 }
 
 void CHROMIUMValuebuffer::deleteObjectImpl(WebGraphicsContext3D* context3d)
 {
     context3d->deleteValuebufferCHROMIUM(m_object);
     m_object = 0;
 }
 
 } // namespace blink