Use new RTCCameraVideoCapturer in AppRTCMobile.

Because the new API doesn't use constraints, refactors settings to instead have a
video resolution setting.

BUG=webrtc:7177

Review-Url: https://codereview.webrtc.org/2778163005
Cr-Commit-Position: refs/heads/master@{#17545}
diff --git a/webrtc/examples/objc/AppRTCMobile/ARDAppClient.h b/webrtc/examples/objc/AppRTCMobile/ARDAppClient.h
index 933dc6b..b613ec9 100644
--- a/webrtc/examples/objc/AppRTCMobile/ARDAppClient.h
+++ b/webrtc/examples/objc/AppRTCMobile/ARDAppClient.h
@@ -10,6 +10,7 @@
 
 #import <Foundation/Foundation.h>
 
+#import "WebRTC/RTCCameraVideoCapturer.h"
 #import "WebRTC/RTCPeerConnection.h"
 #import "WebRTC/RTCVideoTrack.h"
 
@@ -37,6 +38,9 @@
     didChangeConnectionState:(RTCIceConnectionState)state;
 
 - (void)appClient:(ARDAppClient *)client
+    didCreateLocalCapturer:(RTCCameraVideoCapturer *)localCapturer;
+
+- (void)appClient:(ARDAppClient *)client
     didReceiveLocalVideoTrack:(RTCVideoTrack *)localVideoTrack;
 
 - (void)appClient:(ARDAppClient *)client