Replace scoped_ptr with unique_ptr in webrtc/base/

webrtc/base/cryptstring.h

Index: webrtc/base/cryptstring.h
diff --git a/webrtc/base/cryptstring.h b/webrtc/base/cryptstring.h
index a6bae51f89755f2be46a092cb5a46ad99b7754b6..a2c8d0b0a080612e7297b25fa75ee1e48ec5bcd5 100644
--- a/webrtc/base/cryptstring.h
+++ b/webrtc/base/cryptstring.h
@@ -13,11 +13,11 @@
 
 #include <string.h>
 
+#include <memory>
 #include <string>
 #include <vector>
 
 #include "webrtc/base/linked_ptr.h"
-#include "webrtc/base/scoped_ptr.h"
 
 namespace rtc {
 
@@ -62,7 +62,7 @@ public:
   }
   
 private:
-  scoped_ptr<const CryptStringImpl> impl_;
+  std::unique_ptr<const CryptStringImpl> impl_;
 };