Hook up RendererMediaSessionManager with browser side

content/common/media/media_session_messages_android.h

Index: content/common/media/media_session_messages_android.h
diff --git a/content/common/media/media_session_messages_android.h b/content/common/media/media_session_messages_android.h
new file mode 100644
index 0000000000000000000000000000000000000000..4ee2642ea37d016aec9a480982b2606e6fe709cd
--- /dev/null
+++ b/content/common/media/media_session_messages_android.h
@@ -0,0 +1,36 @@
+// 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.
+
+// IPC messages for the Media Session API.
+// Multiply-included message file, hence no include guard.
+
+#include "base/basictypes.h"
+#include "content/common/android/gin_java_bridge_errors.h"
+#include "content/common/content_export.h"
+#include "ipc/ipc_message_macros.h"
+
+#undef IPC_MESSAGE_EXPORT
+#define IPC_MESSAGE_EXPORT CONTENT_EXPORT
+#define IPC_MESSAGE_START MediaSessionMsgStart
+
+// Messages for notifying the render process of media session status -------
+
+IPC_MESSAGE_ROUTED3(MediaSessionMsg_DidActivate,
+                    int /* session_id */,
+                    int /* activation_id */,

[mlamouri (slow - plz ping), 2015/12/02 15:53:31]

nit: request_id

[davve, 2015/12/04 12:43:09]

Done.

+                    bool /* success */)
+
+IPC_MESSAGE_ROUTED2(MediaSessionMsg_DidDeactivate,
+                    int /* session_id */,
+                    int /* deactivation_id */)

[mlamouri (slow - plz ping), 2015/12/02 15:53:31]

ditto

[davve, 2015/12/04 12:43:09]

Done.

+
+// Messages for controlling the media session in browser process ----------
+
+IPC_MESSAGE_ROUTED2(MediaSessionHostMsg_Activate,
+                    int /* session_id */,
+                    int /* activation_id */)

[mlamouri (slow - plz ping), 2015/12/02 15:53:31]

dis tôt

[davve, 2015/12/04 12:43:09]

Done.

+
+IPC_MESSAGE_ROUTED2(MediaSessionHostMsg_Deactivate,
+                    int /* session_id */,
+                    int /* deactivation_id */)

[mlamouri (slow - plz ping), 2015/12/02 15:53:31]

dit tôt

[davve, 2015/12/04 12:43:08]

Done.