Let Flash join and be controlled by media session

content/browser/media/session/pepper_player_delegate.h

+// Copyright 2016 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_SESSION_PEPPER_PLAYER_DELEGATE_H_
+#define CONTENT_BROWSER_MEDIA_SESSION_PEPPER_PLAYER_DELEGATE_H_
+
+#include "base/macros.h"
+#include "content/browser/media/session/media_session_observer.h"
+#include "content/browser/web_contents/web_contents_impl.h"
+
+namespace content {
+
+class PepperWebContentsObserver;
+
+class PepperPlayerDelegate : public MediaSessionObserver {
+ public:
+  // The Id can only be 0 for PepperPlayerDelegate. Declare the constant here so
+  // it can be used elsewhere.
+  static const int kPlayerId;
+
+  PepperPlayerDelegate(
+      WebContentsImpl* contents, int32_t pp_instance);
+  ~PepperPlayerDelegate() override;
+
+  // MediaSessionObserver implementation.
+  void OnSuspend(int player_id) override;
+  void OnResume(int player_id) override;
+  void OnSetVolumeMultiplier(int player_id,
+                             double volume_multiplier) override;
+
+ private:
+  void SetVolume(int player_id, double volume);
+
+  WebContentsImpl* contents_;
+  int32_t pp_instance_;
+
+  DISALLOW_COPY_AND_ASSIGN(PepperPlayerDelegate);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_MEDIA_SESSION_PEPPER_PLAYER_DELEGATE_H_