Add PrefStore::GetValues

components/prefs/overlay_user_pref_store.cc

Index: components/prefs/overlay_user_pref_store.cc
diff --git a/components/prefs/overlay_user_pref_store.cc b/components/prefs/overlay_user_pref_store.cc
index 2b2208ed8214408290c312125e5309689dfecaff..5bdd1d0ec5545561059784a5643af896cf58d95e 100644
--- a/components/prefs/overlay_user_pref_store.cc
+++ b/components/prefs/overlay_user_pref_store.cc
@@ -47,6 +47,21 @@ bool OverlayUserPrefStore::GetValue(const std::string& key,
   return underlay_->GetValue(GetUnderlayKey(key), result);
 }
 
+std::unique_ptr<base::DictionaryValue> OverlayUserPrefStore::GetValues() const {
+  auto overlay_values = overlay_.AsDictionaryValue();
+  auto underlay_values = underlay_->GetValues();
+  auto underlay_iter = base::DictionaryValue::Iterator(*underlay_values);
+  while (!underlay_iter.IsAtEnd()) {
+    const std::string& overlay_key = GetOverlayKey(underlay_iter.key());
+    if (!overlay_values->HasKey(overlay_key)) {
+      overlay_values->SetWithoutPathExpansion(
+          overlay_key, underlay_iter.value().CreateDeepCopy());
+    }
+    underlay_iter.Advance();
+  }
+  return overlay_values;
+}
+
 bool OverlayUserPrefStore::GetMutableValue(const std::string& key,
                                            base::Value** result) {
   if (!ShallBeStoredInOverlay(key))