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

chrome/browser/debugger/devtools_file_helper.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/debugger/devtools_file_helper.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 119 matching lines @@
     return;
   }
 
   if (save_as_dialog_)
     save_as_dialog_->ResetHelper();
 
   const DictionaryValue* file_map =
       profile_->GetPrefs()->GetDictionary(prefs::kDevToolsEditedFiles);
   FilePath initial_path;
 
-  Value* path_value;
+  const Value* path_value;
   if (file_map->Get(base::MD5String(url), &path_value))
     base::GetValueAsFilePath(*path_value, &initial_path);
 
   if (initial_path.empty()) {
     GURL gurl(url);
     std::string suggested_file_name = gurl.is_valid() ?
         gurl.ExtractFileName() : url;
 
     if (suggested_file_name.length() > 20)
       suggested_file_name = suggested_file_name.substr(0, 20);
@@ skipping 39 matching lines @@
   files_map->SetWithoutPathExpansion(base::MD5String(url),
                                      base::CreateFilePathValue(path));
   delegate_->FileSavedAs(url);
 
   BrowserThread::PostTask(
       BrowserThread::FILE, FROM_HERE,
       base::Bind(&DevToolsFileHelper::WriteFile,
                  path,
                  content));
 }