diff --git a/sdk/BUILD.gn b/sdk/BUILD.gn
index 62e42861e3..b13c50ba2a 100644
--- a/sdk/BUILD.gn
+++ b/sdk/BUILD.gn
@@ -700,7 +700,7 @@ if (is_ios || is_mac) {
           ]
 
           if (rtc_use_metal_rendering) {
-            sources += [ "objc/Framework/UnitTests/RTCMTLVideoView_xctest.mm" ]
+            sources += [ "objc/Framework/UnitTests/RTCMTLVideoView_xctest.m" ]
             deps += [ ":metal_objc" ]
           }
 
diff --git a/sdk/objc/Framework/Classes/Metal/RTCMTLNSVideoView.m b/sdk/objc/Framework/Classes/Metal/RTCMTLNSVideoView.m
index ff23bc6e6e..869858e6b4 100644
--- a/sdk/objc/Framework/Classes/Metal/RTCMTLNSVideoView.m
+++ b/sdk/objc/Framework/Classes/Metal/RTCMTLNSVideoView.m
@@ -27,6 +27,7 @@
   id<RTCMTLRenderer> _renderer;
 }
 
+@synthesize delegate = _delegate;
 @synthesize renderer = _renderer;
 @synthesize metalView = _metalView;
 @synthesize videoFrame = _videoFrame;
@@ -105,6 +106,9 @@
 
 - (void)setSize:(CGSize)size {
   _metalView.drawableSize = size;
+  dispatch_async(dispatch_get_main_queue(), ^{
+    [self.delegate videoView:self didChangeVideoSize:size];
+  });
   [_metalView draw];
 }
 
diff --git a/sdk/objc/Framework/Classes/Metal/RTCMTLVideoView.m b/sdk/objc/Framework/Classes/Metal/RTCMTLVideoView.m
index 24dc29f7f3..eff06af81e 100644
--- a/sdk/objc/Framework/Classes/Metal/RTCMTLVideoView.m
+++ b/sdk/objc/Framework/Classes/Metal/RTCMTLVideoView.m
@@ -37,6 +37,7 @@
   int64_t _lastFrameTimeNs;
 }
 
+@synthesize delegate = _delegate;
 @synthesize rendererI420 = _rendererI420;
 @synthesize rendererNV12 = _rendererNV12;
 @synthesize metalView = _metalView;
@@ -144,6 +145,9 @@
 
 - (void)setSize:(CGSize)size {
   self.metalView.drawableSize = size;
+  dispatch_async(dispatch_get_main_queue(), ^{
+    [self.delegate videoView:self didChangeVideoSize:size];
+  });
 }
 
 - (void)renderFrame:(nullable RTCVideoFrame *)frame {
diff --git a/sdk/objc/Framework/Headers/WebRTC/RTCEAGLVideoView.h b/sdk/objc/Framework/Headers/WebRTC/RTCEAGLVideoView.h
index 60c624e0d2..dba1d7ab64 100644
--- a/sdk/objc/Framework/Headers/WebRTC/RTCEAGLVideoView.h
+++ b/sdk/objc/Framework/Headers/WebRTC/RTCEAGLVideoView.h
@@ -18,11 +18,9 @@
 NS_ASSUME_NONNULL_BEGIN
 
 @class RTCEAGLVideoView;
+
 RTC_EXPORT
-@protocol RTCEAGLVideoViewDelegate
-
-- (void)videoView:(RTCEAGLVideoView *)videoView didChangeVideoSize:(CGSize)size;
-
+@protocol RTCEAGLVideoViewDelegate<RTCVideoViewDelegate>
 @end
 
 /**
@@ -32,7 +30,7 @@ RTC_EXPORT
 RTC_EXPORT
 @interface RTCEAGLVideoView : UIView <RTCVideoRenderer>
 
-@property(nonatomic, weak) id<RTCEAGLVideoViewDelegate> delegate;
+@property(nonatomic, weak) id<RTCVideoViewDelegate> delegate;
 
 - (instancetype)initWithFrame:(CGRect)frame
                        shader:(id<RTCVideoViewShading>)shader NS_DESIGNATED_INITIALIZER;
diff --git a/sdk/objc/Framework/Headers/WebRTC/RTCMTLNSVideoView.h b/sdk/objc/Framework/Headers/WebRTC/RTCMTLNSVideoView.h
index 4990e2529e..f82126c388 100644
--- a/sdk/objc/Framework/Headers/WebRTC/RTCMTLNSVideoView.h
+++ b/sdk/objc/Framework/Headers/WebRTC/RTCMTLNSVideoView.h
@@ -13,5 +13,8 @@
 
 NS_AVAILABLE_MAC(10.11)
 @interface RTCMTLNSVideoView : NSView<RTCVideoRenderer>
+
+@property(nonatomic, weak) id<RTCVideoViewDelegate> delegate;
+
 + (BOOL)isMetalAvailable;
 @end
diff --git a/sdk/objc/Framework/Headers/WebRTC/RTCMTLVideoView.h b/sdk/objc/Framework/Headers/WebRTC/RTCMTLVideoView.h
index 226c62a6a1..802e0ff325 100644
--- a/sdk/objc/Framework/Headers/WebRTC/RTCMTLVideoView.h
+++ b/sdk/objc/Framework/Headers/WebRTC/RTCMTLVideoView.h
@@ -32,6 +32,7 @@ NS_CLASS_AVAILABLE_IOS(9)
 
 RTC_EXPORT
 @interface RTCMTLVideoView : UIView <RTCVideoRenderer>
-
+@property(nonatomic, weak) id<RTCVideoViewDelegate> delegate;
 @end
+
 NS_ASSUME_NONNULL_END
diff --git a/sdk/objc/Framework/Headers/WebRTC/RTCNSGLVideoView.h b/sdk/objc/Framework/Headers/WebRTC/RTCNSGLVideoView.h
index 9e6a9ce948..62c79682ef 100644
--- a/sdk/objc/Framework/Headers/WebRTC/RTCNSGLVideoView.h
+++ b/sdk/objc/Framework/Headers/WebRTC/RTCNSGLVideoView.h
@@ -20,15 +20,13 @@
 NS_ASSUME_NONNULL_BEGIN
 
 @class RTCNSGLVideoView;
-@protocol RTCNSGLVideoViewDelegate
-
-- (void)videoView:(RTCNSGLVideoView *)videoView didChangeVideoSize:(CGSize)size;
 
+@protocol RTCNSGLVideoViewDelegate<RTCVideoViewDelegate>
 @end
 
 @interface RTCNSGLVideoView : NSOpenGLView <RTCVideoRenderer>
 
-@property(nonatomic, weak) id<RTCNSGLVideoViewDelegate> delegate;
+@property(nonatomic, weak) id<RTCVideoViewDelegate> delegate;
 
 - (instancetype)initWithFrame:(NSRect)frameRect
                   pixelFormat:(NSOpenGLPixelFormat *)format
diff --git a/sdk/objc/Framework/Headers/WebRTC/RTCVideoRenderer.h b/sdk/objc/Framework/Headers/WebRTC/RTCVideoRenderer.h
index 5e2e820918..7d91f2f14d 100644
--- a/sdk/objc/Framework/Headers/WebRTC/RTCVideoRenderer.h
+++ b/sdk/objc/Framework/Headers/WebRTC/RTCVideoRenderer.h
@@ -30,4 +30,11 @@ RTC_EXPORT
 
 @end
 
+RTC_EXPORT
+@protocol RTCVideoViewDelegate
+
+- (void)videoView:(id<RTCVideoRenderer>)videoView didChangeVideoSize:(CGSize)size;
+
+@end
+
 NS_ASSUME_NONNULL_END
diff --git a/sdk/objc/Framework/UnitTests/RTCMTLVideoView_xctest.mm b/sdk/objc/Framework/UnitTests/RTCMTLVideoView_xctest.m
similarity index 92%
rename from sdk/objc/Framework/UnitTests/RTCMTLVideoView_xctest.mm
rename to sdk/objc/Framework/UnitTests/RTCMTLVideoView_xctest.m
index 8533a31066..a832173b2a 100644
--- a/sdk/objc/Framework/UnitTests/RTCMTLVideoView_xctest.mm
+++ b/sdk/objc/Framework/UnitTests/RTCMTLVideoView_xctest.m
@@ -62,12 +62,8 @@
   id frameMock = OCMClassMock([RTCVideoFrame class]);
   if (hasCVPixelBuffer) {
     CVPixelBufferRef pixelBufferRef;
-    CVPixelBufferCreate(kCFAllocatorDefault,
-                        200,
-                        200,
-                        kCVPixelFormatType_420YpCbCr8Planar,
-                        nullptr,
-                        &pixelBufferRef);
+    CVPixelBufferCreate(
+        kCFAllocatorDefault, 200, 200, kCVPixelFormatType_420YpCbCr8Planar, nil, &pixelBufferRef);
     OCMStub([frameMock buffer])
         .andReturn([[RTCCVPixelBuffer alloc] initWithPixelBuffer:pixelBufferRef]);
   } else {
@@ -247,4 +243,19 @@
   [self.rendererNV12Mock verify];
 }
 
+- (void)testReportsSizeChangesToDelegate {
+  OCMStub([self.classMock isMetalAvailable]).andReturn(YES);
+
+  id delegateMock = OCMProtocolMock(@protocol(RTCVideoViewDelegate));
+  CGSize size = CGSizeMake(640, 480);
+  OCMExpect([delegateMock videoView:[OCMArg any] didChangeVideoSize:size]);
+
+  RTCMTLVideoView *realView = [[RTCMTLVideoView alloc] init];
+  realView.delegate = delegateMock;
+  [realView setSize:size];
+
+  // Delegate method is invoked with a dispatch_async.
+  OCMVerifyAllWithDelay(delegateMock, 1);
+}
+
 @end