Implement MediaSession on top of the WebMediaPlayerDelegate.

content/common/frame_messages.h

 // Copyright 2013 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 interacting with frames.
 // Multiply-included message file, hence no include guard.
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 1264 matching lines @@
                     std::vector<content::ColorSuggestion> /* suggestions */)
 
 // Asks the browser to end the color chooser.
 IPC_MESSAGE_ROUTED1(FrameHostMsg_EndColorChooser, int /* id */)
 
 // Change the selected color in the color chooser.
 IPC_MESSAGE_ROUTED2(FrameHostMsg_SetSelectedColorInColorChooser,
                     int /* id */,
                     SkColor /* color */)
 
-// Notifies the browser that media has started/stopped playing.
-IPC_MESSAGE_ROUTED4(FrameHostMsg_MediaPlayingNotification,
-                    int64_t /* player_cookie, distinguishes instances */,
-                    bool /* has_video */,
-                    bool /* has_audio */,
-                    bool /* is_remote */)
-
-IPC_MESSAGE_ROUTED1(FrameHostMsg_MediaPausedNotification,
-                    int64_t /* player_cookie, distinguishes instances */)
-
 // Notify browser the theme color has been changed.
 IPC_MESSAGE_ROUTED1(FrameHostMsg_DidChangeThemeColor,
                     SkColor /* theme_color */)
 
 // Response for FrameMsg_TextSurroundingSelectionRequest, |startOffset| and
 // |endOffset| are the offsets of the selection in the returned |content|.
 IPC_MESSAGE_ROUTED3(FrameHostMsg_TextSurroundingSelectionResponse,
                     base::string16,  /* content */
                     size_t, /* startOffset */
                     size_t /* endOffset */)
@@ skipping 147 matching lines @@
 IPC_MESSAGE_ROUTED3(FrameHostMsg_FindMatchRects_Reply,
                     int /* version */,
                     std::vector<gfx::RectF> /* rects */,
                     gfx::RectF /* active_rect */)
 #endif
 
 // Adding a new message? Stick to the sort order above: first platform
 // independent FrameMsg, then ifdefs for platform specific FrameMsg, then
 // platform independent FrameHostMsg, then ifdefs for platform specific
 // FrameHostMsg.