Add use-chromium-style-naming option to Blink GC plugin.

tools/clang/blink_gc_plugin/tests/legacy_naming/delayed_parsing.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 "heap/stubs.h"
 
 namespace blink {
 
 struct HeapObject : public GarbageCollected<HeapObject> {
     void trace(Visitor*) { }
 };
 
 template<typename T>
 class TemplateBase
     : public GarbageCollected<TemplateBase<T> > {
 public:
     void trace(Visitor* visitor) { visitor->trace(m_obj); }
 private:
     Member<HeapObject> m_obj;
 };
 
 class Subclass : public TemplateBase<Subclass> {
 };
 
 }