Implement MediaSession (metadata) per frame [NOT READY, HAS DEPENDENCY]

content/browser/media/android/browser_media_session_manager.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 CONTENT_BROWSER_MEDIA_ANDROID_BROWSER_MEDIA_SESSION_MANAGER_H_
 #define CONTENT_BROWSER_MEDIA_ANDROID_BROWSER_MEDIA_SESSION_MANAGER_H_
 
 #include "base/macros.h"
 #include "base/optional.h"
 #include "content/common/content_export.h"
+#include "content/public/common/media_metadata.h"
 
 namespace IPC {
 class Message;
 }  // namespace IPC
 
 namespace content {
 
 class RenderFrameHost;
-struct MediaMetadata;
+class WebContentsImpl;
 
 class CONTENT_EXPORT BrowserMediaSessionManager {
  public:
-  explicit BrowserMediaSessionManager(RenderFrameHost* render_frame_host);
+  explicit BrowserMediaSessionManager(RenderFrameHost* render_frame_host,
+                                      WebContentsImpl* contents);
+  virtual ~BrowserMediaSessionManager();
 
   // Message handlers.
   virtual void OnActivate(int session_id, int request_id);
   virtual void OnDeactivate(int session_id, int request_id);
+  // Handler for SetMetadata message.
+  // Since the message comes from IPC, |insecure_metadata| might be insecure
+  // since it might come from an attacker. The callback should check the its
+  // sanity before any further actions.
   virtual void OnSetMetadata(
-      int session_id, const base::Optional<MediaMetadata>& metadata);
+      int session_id, const base::Optional<MediaMetadata>& insecure_metadata);
+
+  const base::Optional<MediaMetadata>& media_metadata() const {
+    return media_metadata_;
+  }
 
   int GetRoutingID() const;
 
   bool Send(IPC::Message* msg);
 
  private:
   RenderFrameHost* const render_frame_host_;
+  WebContentsImpl* const contents_;
+
+  base::Optional<MediaMetadata> media_metadata_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserMediaSessionManager);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_MEDIA_ANDROID_BROWSER_MEDIA_SESSION_MANAGER_H_