Move ExtensionUnpacker into extensions:: namespace, rename it to Unpacker

chrome/common/chrome_utility_messages.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.
 
 // Multiply-included message file, so no include guard.
 
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
@@ skipping 84 matching lines @@
 // sandbox.
 IPC_MESSAGE_CONTROL1(ChromeUtilityMsg_GetPrinterCapsAndDefaults,
                      std::string /* printer name */)
 
 //------------------------------------------------------------------------------
 // Utility process host messages:
 // These are messages from the utility process to the browser.
 // Reply when the utility process is done unpacking an extension.  |manifest|
 // is the parsed manifest.json file.
 // The unpacker should also have written out files containing the decoded
-// images and message catalogs from the extension. See ExtensionUnpacker for
+// images and message catalogs from the extension. See extensions::Unpacker for
 // details.
 IPC_MESSAGE_CONTROL1(ChromeUtilityHostMsg_UnpackExtension_Succeeded,
                      DictionaryValue /* manifest */)
 
 // Reply when the utility process has failed while unpacking an extension.
 // |error_message| is a user-displayable explanation of what went wrong.
 IPC_MESSAGE_CONTROL1(ChromeUtilityHostMsg_UnpackExtension_Failed,
                      string16 /* error_message, if any */)
 
 // Reply when the utility process is done unpacking and parsing JSON data
@@ skipping 50 matching lines @@
 // capabilities and defaults.
 IPC_MESSAGE_CONTROL2(ChromeUtilityHostMsg_GetPrinterCapsAndDefaults_Succeeded,
                      std::string /* printer name */,
                      printing::PrinterCapsAndDefaults)
 #endif
 
 // Reply when the utility process has failed to obtain the printer
 // capabilities and defaults.
 IPC_MESSAGE_CONTROL1(ChromeUtilityHostMsg_GetPrinterCapsAndDefaults_Failed,
                      std::string /* printer name */)