Add DVLOG_IS_ON() in preparation for adding dvlog_always_on in chromium project.

third_party/WebKit/Source/bindings/core/v8/WindowProxy.h

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 219 matching lines @@
   virtual void DisposeContext(Lifecycle next_status) = 0;
 
   WARN_UNUSED_RESULT v8::Local<v8::Object> AssociateWithWrapper(
       DOMWindow*,
       const WrapperTypeInfo*,
       v8::Local<v8::Object> wrapper);
 
   v8::Isolate* GetIsolate() const { return isolate_; }
   Frame* GetFrame() const { return frame_.Get(); }
 
-#if DCHECK_IS_ON()
+#if DCHECK_IS_ON() || DVLOG_IS_ON()
   void DidAttachGlobalObject() { is_global_object_attached_ = true; }
   void DidDetachGlobalObject() { is_global_object_attached_ = false; }
 #endif
 
  private:
   v8::Isolate* const isolate_;
   const Member<Frame> frame_;
-#if DCHECK_IS_ON()
+#if DCHECK_IS_ON() || DVLOG_IS_ON()
   bool is_global_object_attached_ = false;
 #endif
 
  protected:
   // TODO(dcheng): Consider making these private and using getters.
   const RefPtr<DOMWrapperWorld> world_;
   // |global_proxy_| is the root reference from Blink to v8::Context (a strong
   // reference to the global proxy makes the entire context alive).  In order to
   // discard the v8::Context, |global_proxy_| needs to be a weak reference or
   // to be destroyed.
   ScopedPersistent<v8::Object> global_proxy_;
   Lifecycle lifecycle_;
 
   // TODO(dcheng): Remove this temporary code for debugging
   // https://crbug.com/728693.
   WTF::debug::StackTrace initialization_stack_;
 };
 
 }  // namespace blink
 
 #endif  // WindowProxy_h