Correct const accessors in base/values.(h|cc), Part II (ListValue)

chrome/browser/ui/webui/chromeos/imageburner/imageburner_ui.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/ui/webui/chromeos/imageburner/imageburner_ui.h"
 
 #include "base/bind.h"
 #include "base/file_path.h"
 #include "base/i18n/rtl.h"
 #include "base/string16.h"
@@ skipping 275 matching lines @@
     GetDataSizeText(amount_finished, &finished);
     string16 total;
     GetDataSizeText(amount_total, &total);
     *progress_text = l10n_util::GetStringFUTF16(message_id, finished, total);
   }
 
   // device_path has to be previously created.
   void ExtractTargetedDevicePath(const ListValue& list_value,
                                  int index,
                                  FilePath* device_path) {
-    Value* list_member;
+    const Value* list_member;
     if (list_value.Get(index, &list_member) &&
         list_member->GetType() == Value::TYPE_STRING) {
       const StringValue* string_value =
           static_cast<const StringValue*>(list_member);
       std::string image_dest;
       string_value->GetAsString(&image_dest);
       *device_path = FilePath(image_dest);
     } else {
       LOG(ERROR) << "Unable to get path string";
       device_path->clear();
@@ skipping 18 matching lines @@
 
 ImageBurnUI::ImageBurnUI(content::WebUI* web_ui) : WebUIController(web_ui) {
   chromeos::imageburner::WebUIHandler* handler =
       new chromeos::imageburner::WebUIHandler(web_ui->GetWebContents());
   web_ui->AddMessageHandler(handler);
 
   Profile* profile = Profile::FromWebUI(web_ui);
   ChromeURLDataManager::AddDataSource(profile,
       chromeos::imageburner::CreateImageburnerUIHTMLSource());
 }