[MediaSession] Add playbackState attribute to Blink MediaSession and use it to determine playback s…

third_party/WebKit/public/platform/modules/mediasession/media_session.mojom

Index: third_party/WebKit/public/platform/modules/mediasession/media_session.mojom
diff --git a/third_party/WebKit/public/platform/modules/mediasession/media_session.mojom b/third_party/WebKit/public/platform/modules/mediasession/media_session.mojom
index 3d4df05aee5177ab5bfe9b687af733bf86d8d2b8..4216e807ab5d2d3d153a4c3bdd1023f09a92a112 100644
--- a/third_party/WebKit/public/platform/modules/mediasession/media_session.mojom
+++ b/third_party/WebKit/public/platform/modules/mediasession/media_session.mojom
@@ -12,7 +12,6 @@ import "url/mojo/url.mojom";
 enum MediaSessionAction {
      PLAY,
      PAUSE,
-     PLAY_PAUSE,
      PREVIOUS_TRACK,
      NEXT_TRACK,
      SEEK_BACKWARD,
@@ -21,6 +20,12 @@ enum MediaSessionAction {
      LAST = SEEK_FORWARD,
 };
 
+enum MediaSessionPlaybackState {
+     NONE,
+     PAUSED,
+     PLAYING,
+};
+
 // Album art in MediaMetadata
 // Spec: https://wicg.github.io/mediasession/
 struct MediaImage {
@@ -49,6 +54,9 @@ interface MediaSessionService {
   // media control actions.
   SetClient(MediaSessionClient client);
 
+  // Notifies the browser that the page specified its current playback state.
+  SetPlaybackState(MediaSessionPlaybackState state);
+
   // Notifies the browser that the metadata is set, |metadata| will be displayed
   // on the UI.
   SetMetadata(MediaMetadata? metadata);