Replace scoped_ptr with unique_ptr in talk/

talk/app/webrtc/objc/RTCPeerConnectionFactory.mm

Index: talk/app/webrtc/objc/RTCPeerConnectionFactory.mm
diff --git a/talk/app/webrtc/objc/RTCPeerConnectionFactory.mm b/talk/app/webrtc/objc/RTCPeerConnectionFactory.mm
index a60263a12f7c61bcd7c63db247be60379a8438f5..cd81f35e2a1864efcbeec4e0e6f431219d545713 100644
--- a/talk/app/webrtc/objc/RTCPeerConnectionFactory.mm
+++ b/talk/app/webrtc/objc/RTCPeerConnectionFactory.mm
@@ -31,6 +31,7 @@
 
 #import "RTCPeerConnectionFactory+Internal.h"
 
+#include <memory>
 #include <vector>
 
 #import "RTCAudioTrack+Internal.h"
@@ -55,8 +56,8 @@
 #include "webrtc/base/ssladapter.h"
 
 @implementation RTCPeerConnectionFactory {
-  rtc::scoped_ptr<rtc::Thread> _signalingThread;
-  rtc::scoped_ptr<rtc::Thread> _workerThread;
+  std::unique_ptr<rtc::Thread> _signalingThread;
+  std::unique_ptr<rtc::Thread> _workerThread;
 }
 
 @synthesize nativeFactory = _nativeFactory;