Convert utility process extension Unpacker IPC to mojo

chrome/utility/extensions/extensions_handler.h

 // Copyright 2014 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_UTILITY_EXTENSIONS_EXTENSIONS_HANDLER_H_
 #define CHROME_UTILITY_EXTENSIONS_EXTENSIONS_HANDLER_H_
 
 #include <stdint.h>
 
 #include "base/base64.h"
@@ skipping 18 matching lines @@
 namespace extensions {
 
 // Dispatches IPCs for Chrome extensions utility messages.
 class ExtensionsHandler : public UtilityMessageHandler {
  public:
   ExtensionsHandler();
   ~ExtensionsHandler() override;
 
   static void PreSandboxStartup();
 
+  static void UtilityThreadStarted();
+
   // TODO(noel): consider moving this API to the UtilityMessageHandler
   // interface.
   static void ExposeInterfacesToBrowser(
       service_manager::InterfaceRegistry* registry,
       ChromeContentUtilityClient* utility_client,
       bool running_elevated);
 
   // UtilityMessageHandler:
   bool OnMessageReceived(const IPC::Message& message) override;
 
@@ skipping 16 matching lines @@
 #endif  // defined(OS_WIN) || defined(OS_MACOSX)
 
   UtilityHandler utility_handler_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionsHandler);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_UTILITY_EXTENSIONS_EXTENSIONS_HANDLER_H_