extended android jni with onMediaSessionSetPositionState

support/android/apk/servoapp/src/main/java/org/mozilla/servo/MainActivity.java

@@ -255,4 +255,15 @@ public void onMediaSessionPlaybackStateChange(int state) {
           return;
       }
     }
+
+    @Override
+    public void onMediaSessionSetPositionState(float duration, float position, float playbackRate) {
+        Log.d("onMediaSessionSetPositionState", duration + " " + position + " " + playbackRate);
+        if (mMediaSession == null) {
+            mMediaSession = new MediaSession(mServoView, this, getApplicationContext());
+        }
+
+        mMediaSession.setPositionState(duration, position, playbackRate);
+        return;
+    }
 }

support/android/apk/servoapp/src/main/java/org/mozilla/servo/MediaSession.java

@@ -192,4 +192,8 @@ public void updateMetadata(String title, String artist, String album) {
         showMediaSessionControls();
       }
     }
-}
+
+    // Not implemented
+    // see https://github.com/servo/servo/pull/24885#discussion_r352496117
+    public void setPositionState(float duration, float position, float playbackRate) {}
+}

support/android/apk/servoview/src/main/java/org/mozilla/servoview/JNIServo.java

@@ -115,6 +115,8 @@
         void onMediaSessionMetadata(String title, String artist, String album);
 
         void onMediaSessionPlaybackStateChange(int state);
+
+        void onMediaSessionSetPositionState(float duration, float position, float playbackRate);
     }
 }
 

support/android/apk/servoview/src/main/java/org/mozilla/servoview/Servo.java

@@ -192,6 +192,8 @@ public void mediaSessionAction(int action) {
         void onMediaSessionMetadata(String title, String artist, String album);
 
         void onMediaSessionPlaybackStateChange(int state);
+
+        void onMediaSessionSetPositionState(float duration, float position, float playbackRate);
     }
 
     public interface RunCallback {
@@ -285,5 +287,9 @@ public void onMediaSessionMetadata(String title, String artist, String album) {
         public void onMediaSessionPlaybackStateChange(int state) {
             mRunCallback.inUIThread(() -> mClient.onMediaSessionPlaybackStateChange(state));
         }
+
+        public void onMediaSessionSetPositionState(float duration, float position, float playbackRate) {
+            mRunCallback.inUIThread(() -> mClient.onMediaSessionSetPositionState(duration, position, playbackRate));
+        }
     }
 }