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

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

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/extensions/api/omnibox/omnibox_api.h"
 
 #include "base/json/json_writer.h"
 #include "base/lazy_instance.h"
 #include "base/metrics/histogram.h"
 #include "base/string_util.h"
@@ skipping 148 matching lines @@
                                           bool require_content) {
   if (!value.GetString(kSuggestionContent, &content) && require_content)
     return false;
 
   if (!value.GetString(kSuggestionDescription, &description))
     return false;
 
   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;
     }
     for (size_t i = 0; i < styles->GetSize(); ++i) {
       base::DictionaryValue* style = NULL;
       int offset, type;
       if (!styles->GetDictionary(i, &style))
         return false;
       if (!style->GetInteger(kDescriptionStylesType, &type))
@@ skipping 116 matching lines @@
     for (size_t i = 0; i < description_styles.size(); ++i) {
       if (description_styles[i].offset > placeholder)
         description_styles[i].offset += replacement.length() - 2;
     }
   }
 
   match->contents.assign(description);
 }
 
 }  // namespace extensions