Add stats overlay to iOS AppRTCDemo.

webrtc/examples/objc/AppRTCDemo/ios/ARDVideoCallViewController.m

Index: webrtc/examples/objc/AppRTCDemo/ios/ARDVideoCallViewController.m
diff --git a/webrtc/examples/objc/AppRTCDemo/ios/ARDVideoCallViewController.m b/webrtc/examples/objc/AppRTCDemo/ios/ARDVideoCallViewController.m
index 36c0902981910d7cbac5c413ad9110f118f0e19d..a26068f213d7724895e48f9c356094e98bc1af6a 100644
--- a/webrtc/examples/objc/AppRTCDemo/ios/ARDVideoCallViewController.m
+++ b/webrtc/examples/objc/AppRTCDemo/ios/ARDVideoCallViewController.m
@@ -88,6 +88,12 @@
 }
 
 - (void)appClient:(ARDAppClient *)client
+      didGetStats:(NSArray *)stats {
+  _videoCallView.statsView.stats = stats;
+  [_videoCallView setNeedsLayout];
+}
+
+- (void)appClient:(ARDAppClient *)client
          didError:(NSError *)error {
   NSString *message =
       [NSString stringWithFormat:@"%@", error.localizedDescription];
@@ -107,6 +113,11 @@
   [self switchCamera];
 }
 
+- (void)videoCallViewDidEnableStats:(ARDVideoCallView *)view {
+  _client.shouldGetStats = YES;
+  _videoCallView.statsView.hidden = NO;
+}
+
 #pragma mark - Private
 
 - (void)setLocalVideoTrack:(RTCVideoTrack *)localVideoTrack {