Make MTLView content mode settable.

We want to allow the application to set it's own content mode.

Bug: b/73147161
Change-Id: I60fab454353a4c39731e49b7b6066e51d8e9a94d
Reviewed-on: https://webrtc-review.googlesource.com/70501
Commit-Queue: Kári Helgason <kthelgason@webrtc.org>
Reviewed-by: Anders Carlsson <andersc@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22962}
diff --git a/sdk/objc/Framework/Headers/WebRTC/RTCMTLVideoView.h b/sdk/objc/Framework/Headers/WebRTC/RTCMTLVideoView.h
index 802e0ff..266f2c2 100644
--- a/sdk/objc/Framework/Headers/WebRTC/RTCMTLVideoView.h
+++ b/sdk/objc/Framework/Headers/WebRTC/RTCMTLVideoView.h
@@ -32,7 +32,11 @@
 
 RTC_EXPORT
 @interface RTCMTLVideoView : UIView <RTCVideoRenderer>
+
 @property(nonatomic, weak) id<RTCVideoViewDelegate> delegate;
+
+- (void)setVideoContentMode:(UIViewContentMode)mode;
+
 @end
 
 NS_ASSUME_NONNULL_END