Convert //chrome/browser/sync from scoped_ptr to std::unique_ptr

chrome/browser/sync/test/integration/preferences_helper.cc

Index: chrome/browser/sync/test/integration/preferences_helper.cc
diff --git a/chrome/browser/sync/test/integration/preferences_helper.cc b/chrome/browser/sync/test/integration/preferences_helper.cc
index 5e76c0995abb622527cd4c3389b3c9d37663941b..f9f7778a12819743c9e3a40660769db55796b4d2 100644
--- a/chrome/browser/sync/test/integration/preferences_helper.cc
+++ b/chrome/browser/sync/test/integration/preferences_helper.cc
@@ -266,7 +266,7 @@ const char* PrefMatchChecker::GetPath() const {
 }
 
 void PrefMatchChecker::RegisterPrefListener(PrefService* pref_service) {
-  scoped_ptr<PrefChangeRegistrar> registrar(new PrefChangeRegistrar());
+  std::unique_ptr<PrefChangeRegistrar> registrar(new PrefChangeRegistrar());
   registrar->Init(pref_service);
   registrar->Add(path_,
                  base::Bind(&PrefMatchChecker::CheckExitCondition,