Media Session API: use MediaMetadata in the browser process.

content/browser/android/web_contents_observer_proxy.h

Index: content/browser/android/web_contents_observer_proxy.h
diff --git a/content/browser/android/web_contents_observer_proxy.h b/content/browser/android/web_contents_observer_proxy.h
index d37f718c64d04b712c337a247731ebeb23681c3a..af0895dc6693f3ea23fdda5d44268333e38b0639 100644
--- a/content/browser/android/web_contents_observer_proxy.h
+++ b/content/browser/android/web_contents_observer_proxy.h
@@ -73,7 +73,8 @@ class WebContentsObserverProxy : public WebContentsObserver {
       const GURL& url,
       NavigationController::ReloadType reload_type) override;
   void MediaSessionStateChanged(bool is_controllable,
-                                bool is_suspended) override;
+                                bool is_suspended,
+                                const MediaMetadata& metadata) override;
   void SetToBaseURLForDataURLIfNeeded(std::string* url);
 
   void DidFailLoadInternal(bool is_provisional_load,