Replace scoped_ptr with unique_ptr in talk/

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 9d82283142c19baf3283db2a905464816220714d..8b4e454a6ebe1434c7f54a42d158295fb9163a47 100644
--- a/talk/app/webrtc/objc/RTCAVFoundationVideoSource.mm
+++ b/talk/app/webrtc/objc/RTCAVFoundationVideoSource.mm
@@ -32,12 +32,14 @@
 #import "RTCPeerConnectionFactory+Internal.h"
 #import "RTCVideoSource+Internal.h"
 
+#include <memory>
+
 @implementation RTCAVFoundationVideoSource
 
 - (instancetype)initWithFactory:(RTCPeerConnectionFactory*)factory
                     constraints:(RTCMediaConstraints*)constraints {
   NSParameterAssert(factory);
-  rtc::scoped_ptr<webrtc::AVFoundationVideoCapturer> capturer;
+  std::unique_ptr<webrtc::AVFoundationVideoCapturer> capturer;
   capturer.reset(new webrtc::AVFoundationVideoCapturer());
   rtc::scoped_refptr<webrtc::VideoTrackSourceInterface> source =
       factory.nativeFactory->CreateVideoSource(capturer.release(), constraints.constraints);