Replace SetCapturer and SetCaptureDevice by SetSource.

talk/app/webrtc/objc/RTCAVFoundationVideoSource.mm

Index: talk/app/webrtc/objc/RTCAVFoundationVideoSource.mm
diff --git a/talk/app/webrtc/objc/RTCAVFoundationVideoSource.mm b/talk/app/webrtc/objc/RTCAVFoundationVideoSource.mm
index 660bb4d6cbfb28a4f65ed8366529c622b6618e11..8dc0fe900c076fef449c63103ee09ae4ad8ffc6e 100644
--- a/talk/app/webrtc/objc/RTCAVFoundationVideoSource.mm
+++ b/talk/app/webrtc/objc/RTCAVFoundationVideoSource.mm
@@ -34,15 +34,20 @@
 
 #include <memory>
 
-@implementation RTCAVFoundationVideoSource
+@implementation RTCAVFoundationVideoSource {
+  webrtc::AVFoundationVideoCapturer *_capturer;
+}
 
 - (instancetype)initWithFactory:(RTCPeerConnectionFactory*)factory
                     constraints:(RTCMediaConstraints*)constraints {
   NSParameterAssert(factory);
-  std::unique_ptr<webrtc::AVFoundationVideoCapturer> capturer;
-  capturer.reset(new webrtc::AVFoundationVideoCapturer());
+  // We pass ownership of the capturer to the source, but since we own
+  // the source, it should be ok to keep a raw pointer to the
+  // capturer.
+  _capturer = new webrtc::AVFoundationVideoCapturer();
   rtc::scoped_refptr<webrtc::VideoTrackSourceInterface> source =
-      factory.nativeFactory->CreateVideoSource(capturer.release(), constraints.constraints);
+      factory.nativeFactory->CreateVideoSource(_capturer,
+                                               constraints.constraints);
   return [super initWithMediaSource:source];
 }
 
@@ -63,12 +68,7 @@
 }
 
 - (webrtc::AVFoundationVideoCapturer*)capturer {
-  cricket::VideoCapturer* capturer = self.videoSource->GetVideoCapturer();
-  // This should be safe because no one should have changed the underlying video
-  // source.
-  webrtc::AVFoundationVideoCapturer* foundationCapturer =
-      static_cast<webrtc::AVFoundationVideoCapturer*>(capturer);
-  return foundationCapturer;
+  return _capturer;
 }
 
 @end