components: Use stl utilities from the base namespace

components/user_prefs/tracked/segregated_pref_store.cc

Index: components/user_prefs/tracked/segregated_pref_store.cc
diff --git a/components/user_prefs/tracked/segregated_pref_store.cc b/components/user_prefs/tracked/segregated_pref_store.cc
index c5a6e25c2f3715bc410a049652401cb633ec7a7d..af8dfe34be7b3ab1e17294cf041b572382ba39ef 100644
--- a/components/user_prefs/tracked/segregated_pref_store.cc
+++ b/components/user_prefs/tracked/segregated_pref_store.cc
@@ -166,14 +166,16 @@ SegregatedPrefStore::~SegregatedPrefStore() {
 }
 
 PersistentPrefStore* SegregatedPrefStore::StoreForKey(const std::string& key) {
-  return (ContainsKey(selected_preference_names_, key)
+  return (base::ContainsKey(selected_preference_names_, key)
               ? selected_pref_store_
-              : default_pref_store_).get();
+              : default_pref_store_)
+      .get();
 }
 
 const PersistentPrefStore* SegregatedPrefStore::StoreForKey(
     const std::string& key) const {
-  return (ContainsKey(selected_preference_names_, key)
+  return (base::ContainsKey(selected_preference_names_, key)
               ? selected_pref_store_
-              : default_pref_store_).get();
+              : default_pref_store_)
+      .get();
 }