Add new view that renders local video using AVCaptureLayerPreview.

BUG=

Review URL: https://codereview.webrtc.org/1497393002

Cr-Commit-Position: refs/heads/master@{#10940}
diff --git a/webrtc/examples/objc/AppRTCDemo/ios/ARDVideoCallView.h b/webrtc/examples/objc/AppRTCDemo/ios/ARDVideoCallView.h
index 209bcd4..378281d 100644
--- a/webrtc/examples/objc/AppRTCDemo/ios/ARDVideoCallView.h
+++ b/webrtc/examples/objc/AppRTCDemo/ios/ARDVideoCallView.h
@@ -10,6 +10,7 @@
 
 #import <UIKit/UIKit.h>
 
+#import "webrtc/base/objc/RTCCameraPreviewView.h"
 #import "RTCEAGLVideoView.h"
 
 #import "ARDStatsView.h"
@@ -33,7 +34,7 @@
 @interface ARDVideoCallView : UIView
 
 @property(nonatomic, readonly) UILabel *statusLabel;
-@property(nonatomic, readonly) RTCEAGLVideoView *localVideoView;
+@property(nonatomic, readonly) RTCCameraPreviewView *localVideoView;
 @property(nonatomic, readonly) RTCEAGLVideoView *remoteVideoView;
 @property(nonatomic, readonly) ARDStatsView *statsView;
 @property(nonatomic, weak) id<ARDVideoCallViewDelegate> delegate;