PPAPI: Refactor MessageChannel to prep for sync postMessae

components/nacl/renderer/nacl_helper.h

+// Copyright 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.
+
+#ifndef COMPONENTS_NACL_RENDERER_NACL_HELPER_H_
+#define COMPONENTS_NACL_RENDERER_NACL_HELPER_H_
+
+#include "base/compiler_specific.h"
+#include "content/public/renderer/render_frame_observer.h"
+
+namespace nacl {
+
+// This class listens for Pepper creation events from the RenderFrame. For the
+// NaCl trusted plugin, it configures it as an external plugin host.
+// TODO(dmichael): When the trusted plugin goes away, we need to figure out the
+//                 right event to watch for.
+class NaClHelper : public content::RenderFrameObserver {
+ public:
+  explicit NaClHelper(content::RenderFrame* render_frame);
+  virtual ~NaClHelper();
+
+  // RenderFrameObserver.
+  virtual void DidCreatePepperPlugin(content::RendererPpapiHost* host) OVERRIDE;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(NaClHelper);
+};
+
+}  // namespace nacl
+
+#endif  // COMPONENTS_NACL_RENDERER_NACL_HELPER_H_