Remove raw DictionaryValue::Set in //chrome

chrome/browser/supervised_user/supervised_user_pref_store_unittest.cc

Index: chrome/browser/supervised_user/supervised_user_pref_store_unittest.cc
diff --git a/chrome/browser/supervised_user/supervised_user_pref_store_unittest.cc b/chrome/browser/supervised_user/supervised_user_pref_store_unittest.cc
index 813be5204bbaccd9b4fc5c9cab5c22268cc2d852..2f6008054308bae3c22f6f0ce1ef576c40b51209 100644
--- a/chrome/browser/supervised_user/supervised_user_pref_store_unittest.cc
+++ b/chrome/browser/supervised_user/supervised_user_pref_store_unittest.cc
@@ -5,6 +5,7 @@
 #include <set>
 #include <string>
 
+#include "base/memory/ptr_util.h"
 #include "base/memory/ref_counted.h"
 #include "base/values.h"
 #include "chrome/browser/net/safe_search_util.h"
@@ -59,7 +60,7 @@ void SupervisedUserPrefStoreFixture::OnPrefValueChanged(
     const std::string& key) {
   const base::Value* value = NULL;
   ASSERT_TRUE(pref_store_->GetValue(key, &value));
-  changed_prefs_.Set(key, value->DeepCopy());
+  changed_prefs_.Set(key, base::MakeUnique<base::Value>(*value));
 }
 
 void SupervisedUserPrefStoreFixture::OnInitializationCompleted(bool succeeded) {