Replace scoped_ptr with unique_ptr in talk/

talk/app/webrtc/objc/RTCMediaConstraints.mm

Index: talk/app/webrtc/objc/RTCMediaConstraints.mm
diff --git a/talk/app/webrtc/objc/RTCMediaConstraints.mm b/talk/app/webrtc/objc/RTCMediaConstraints.mm
index f5cfe33619c114454cdeff9d3347b83040da1ebf..a79afb1794117767dc490d6b3de35a79a8346c3d 100644
--- a/talk/app/webrtc/objc/RTCMediaConstraints.mm
+++ b/talk/app/webrtc/objc/RTCMediaConstraints.mm
@@ -33,13 +33,13 @@
 
 #import "RTCPair.h"
 
-#include "webrtc/base/scoped_ptr.h"
+#include <memory>
 
 // TODO(hughv):  Add accessors for mandatory and optional constraints.
 // TODO(hughv):  Add description.
 
 @implementation RTCMediaConstraints {
-  rtc::scoped_ptr<webrtc::RTCMediaConstraintsNative> _constraints;
+  std::unique_ptr<webrtc::RTCMediaConstraintsNative> _constraints;
   webrtc::MediaConstraintsInterface::Constraints _mandatory;
   webrtc::MediaConstraintsInterface::Constraints _optional;
 }