Correct const accessors in base/values.(h|cc)

chrome/browser/extensions/api/omnibox/omnibox_api.cc

Index: chrome/browser/extensions/api/omnibox/omnibox_api.cc
diff --git a/chrome/browser/extensions/api/omnibox/omnibox_api.cc b/chrome/browser/extensions/api/omnibox/omnibox_api.cc
index de0478870f67a8dcef0c9b0ff2322087ab9fef7b..16d0a09072fa0e69507ca3ffcaf879e6c7e243cd 100644
--- a/chrome/browser/extensions/api/omnibox/omnibox_api.cc
+++ b/chrome/browser/extensions/api/omnibox/omnibox_api.cc
@@ -166,14 +166,14 @@ bool ExtensionOmniboxSuggestion::Populate(const base::DictionaryValue& value,
   description_styles.clear();
   if (value.HasKey(kSuggestionDescriptionStyles)) {
     // This version comes from the extension.
-    ListValue* styles = NULL;
+    const ListValue* styles = NULL;
     if (!value.GetList(kSuggestionDescriptionStyles, &styles) ||
         !ReadStylesFromValue(*styles)) {
       return false;
     }
   } else if (value.HasKey(kSuggestionDescriptionStylesRaw)) {
     // This version comes from ToValue(), which we use to persist to disk.
-    ListValue* styles = NULL;
+    const ListValue* styles = NULL;
     if (!value.GetList(kSuggestionDescriptionStylesRaw, &styles) ||
         styles->empty()) {
       return false;