Convert //sync from scoped_ptr to std::unique_ptr

sync/api/sync_error.h

Index: sync/api/sync_error.h
diff --git a/sync/api/sync_error.h b/sync/api/sync_error.h
index d2832a51d23fa8781acf43add5e728b0893747de..a9d521f4fe4d14916908dec62a5cbbe7916c866b 100644
--- a/sync/api/sync_error.h
+++ b/sync/api/sync_error.h
@@ -6,9 +6,9 @@
 #define SYNC_API_SYNC_ERROR_H_
 
 #include <iosfwd>
+#include <memory>
 #include <string>
 
-#include "base/memory/scoped_ptr.h"
 #include "sync/base/sync_export.h"
 #include "sync/internal_api/public/base/model_type.h"
 
@@ -115,7 +115,7 @@ class SYNC_EXPORT SyncError {
   void Clear();
 
   // scoped_ptr is necessary because Location objects aren't assignable.
-  scoped_ptr<tracked_objects::Location> location_;
+  std::unique_ptr<tracked_objects::Location> location_;
   std::string message_;
   ModelType model_type_;
   ErrorType error_type_;