Revert of Change extension icon load errors to warnings

chrome/common/extensions/api/extension_action/action_info.h

 // 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.
 
 #ifndef CHROME_COMMON_EXTENSIONS_API_EXTENSION_ACTION_ACTION_INFO_H_
 #define CHROME_COMMON_EXTENSIONS_API_EXTENSION_ACTION_ACTION_INFO_H_
 
 #include <string>
 
 #include "base/strings/string16.h"
@@ skipping 14 matching lines @@
   ~ActionInfo();
 
   // The types of extension actions.
   enum Type {
     TYPE_BROWSER,
     TYPE_PAGE,
     TYPE_SYSTEM_INDICATOR,
   };
 
   // Loads an ActionInfo from the given DictionaryValue.
-  static scoped_ptr<ActionInfo> Load(Extension* extension,
+  static scoped_ptr<ActionInfo> Load(const Extension* extension,
                                      const base::DictionaryValue* dict,
                                      base::string16* error);
 
   // Returns the extension's browser action, if any.
   static const ActionInfo* GetBrowserActionInfo(const Extension* extension);
 
   // Returns the extension's page action, if any.
   static const ActionInfo* GetPageActionInfo(const Extension* extension);
 
   // Returns the extension's system indicator, if any.
@@ skipping 17 matching lines @@
   ExtensionIconSet default_icon;
   std::string default_title;
   GURL default_popup_url;
   // action id -- only used with legacy page actions API.
   std::string id;
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_COMMON_EXTENSIONS_API_EXTENSION_ACTION_ACTION_INFO_H_