Fixed background playback behind notification center.

RCTVideo.m

@@ -63,6 +63,11 @@ static NSString *const playbackBufferEmptyKeyPath = @"playbackBufferEmpty";
                                                  name:UIApplicationWillResignActiveNotification
                                                object:nil];
 
+    [[NSNotificationCenter defaultCenter] addObserver:self
+                                             selector:@selector(applicationDidEnterBackground:)
+                                                 name:UIApplicationDidEnterBackgroundNotification
+                                               object:nil];
+
     [[NSNotificationCenter defaultCenter] addObserver:self
                                              selector:@selector(applicationWillEnterForeground:)
                                                  name:UIApplicationWillEnterForegroundNotification
@@ -119,15 +124,20 @@ static NSString *const playbackBufferEmptyKeyPath = @"playbackBufferEmpty";
 
 - (void)applicationWillResignActive:(NSNotification *)notification
 {
-  if (_playInBackground) {
-    // Needed to play sound in background. See https://developer.apple.com/library/ios/qa/qa1668/_index.html
-    [_playerLayer setPlayer:nil];
-  } else if (!_paused) {
+  if (!_paused && !_playInBackground) {
     [_player pause];
     [_player setRate:0.0];
   }
 }
 
+- (void)applicationDidEnterBackground:(NSNotification *)notification
+{
+    if (_playInBackground) {
+        // Needed to play sound in background. See https://developer.apple.com/library/ios/qa/qa1668/_index.html
+        [_playerLayer setPlayer:nil];
+    }
+}
+
 - (void)applicationWillEnterForeground:(NSNotification *)notification
 {
   [self applyModifiers];