Allow MediaSession in iframes to be routed

content/public/browser/media_session_observer.h

Index: content/public/browser/media_session_observer.h
diff --git a/content/public/browser/media_session_observer.h b/content/public/browser/media_session_observer.h
index 781c65a52f94a4aca759eb5f2735b5d6fa968f98..34f69e8ff8a54ad719a4eb0d7585f912b11133e0 100644
--- a/content/public/browser/media_session_observer.h
+++ b/content/public/browser/media_session_observer.h
@@ -5,6 +5,8 @@
 #ifndef CONTENT_PUBLIC_BROWSER_MEDIA_SESSION_OBSERVER_H_
 #define CONTENT_PUBLIC_BROWSER_MEDIA_SESSION_OBSERVER_H_
 
+#include <set>
+
 #include "base/macros.h"
 #include "base/optional.h"
 #include "content/common/content_export.h"
@@ -41,13 +43,9 @@ class CONTENT_EXPORT MediaSessionObserver {
   virtual void MediaSessionMetadataChanged(
       const base::Optional<MediaMetadata>& metadata) {}
 
-  // Called when media session action is enabled.
-  virtual void MediaSessionEnabledAction(
-      blink::mojom::MediaSessionAction action) {}
-
-  // Called when media session action is disabled.
-  virtual void MediaSessionDisabledAction(
-      blink::mojom::MediaSessionAction action) {}
+  // Called when the media session action list has changed.
+  virtual void MediaSessionActionsChanged(
+      const std::set<blink::mojom::MediaSessionAction>& action) {}
 
  protected:
   // Create a MediaSessionObserver and start observing a session.