Parse messages.json in ExtensionUnpacker (like we do for manifest)....

chrome/browser/utility_process_host.h

 // Copyright (c) 2009 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_BROWSER_UTILITY_PROCESS_HOST_H_
 #define CHROME_BROWSER_UTILITY_PROCESS_HOST_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 17 matching lines @@
   // get results back.  All functions are called on the thread passed along
   // to UtilityProcessHost.
   class Client : public base::RefCountedThreadSafe<Client> {
    public:
     Client() {}
 
     // Called when the process has crashed.
     virtual void OnProcessCrashed() {}
 
     // Called when the extension has unpacked successfully.  |manifest| is the
-    // parsed manifest.json file.  |images| contains a list of decoded images
-    // and the associated paths where those images live on disk.
-    virtual void OnUnpackExtensionSucceeded(const DictionaryValue& manifest) {}
+    // parsed manifest.json file.  |catalogs| contains list of all parsed
+    // message catalogs.  |images| contains a list of decoded images and the
+    // associated paths where those images live on disk.
+    virtual void OnUnpackExtensionSucceeded(const DictionaryValue& manifest,
+                                            const DictionaryValue& catalogs) {}
 
     // Called when an error occurred while unpacking the extension.
     // |error_message| contains a description of the problem.
     virtual void OnUnpackExtensionFailed(const std::string& error_message) {}
 
     // Called when the web resource has been successfully parsed.  |json_data|
     // contains the parsed list of web resource items downloaded from the
     // web resource server.
     virtual void OnUnpackWebResourceSucceeded(
         const DictionaryValue& json_data) {}
 
     // Called when an error occurred while parsing the resource data.
     // |error_message| contains a description of the problem.
-    virtual void OnUnpackWebResourceFailed(
-        const std::string& error_message) {}
+    virtual void OnUnpackWebResourceFailed(const std::string& error_message) {}
 
     // Called when an update manifest xml file was successfully parsed.
     virtual void OnParseUpdateManifestSucceeded(
         const UpdateManifest::ResultList& list) {}
 
     // Called when an update manifest xml file failed parsing. |error_message|
     // contains details suitable for logging.
     virtual void OnParseUpdateManifestFailed(
         const std::string& error_message) {}
 
@@ skipping 55 matching lines @@
   }
 
   // A pointer to our client interface, who will be informed of progress.
   scoped_refptr<Client> client_;
   ChromeThread::ID client_thread_id_;
 
   DISALLOW_COPY_AND_ASSIGN(UtilityProcessHost);
 };
 
 #endif  // CHROME_BROWSER_UTILITY_PROCESS_HOST_H_