Minor comment and style updates for on-demand update check code.

chrome/browser/google/google_update_win.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/google/google_update_win.h"
 
 #include <atlbase.h>
 #include <atlcom.h>
 
 #include "base/bind.h"
@@ skipping 121 matching lines @@
     base::win::ScopedComPtr<IGoogleUpdate3Web>* google_update) {
   if (g_google_update_factory)
     return g_google_update_factory->Run(google_update);
 
   // For a user-level install, update checks and updates can both be done by a
   // normal user with the UserClass.
   if (!system_level_install)
     return google_update->CreateInstance(CLSID_GoogleUpdate3WebUserClass);
 
   // For a system-level install, update checks can be done by a normal user with
-  // the ServiceClass.
+  // the MachineClass.
   if (!install_update_if_possible)
     return google_update->CreateInstance(CLSID_GoogleUpdate3WebMachineClass);
 
   // For a system-level install, an update requires Admin privileges for writing
-  // to %ProgramFiles%. Elevate while instantiating the ServiceClass.
+  // to %ProgramFiles%. Elevate while instantiating the MachineClass.
   return CoCreateInstanceAsAdmin(CLSID_GoogleUpdate3WebMachineClass,
                                  IID_IGoogleUpdate3Web, elevation_window,
                                  google_update->ReceiveVoid());
 }
 
 // UpdateCheckDriver -----------------------------------------------------------
 
 // A driver that is created and destroyed on the caller's thread and drives
 // Google Update on another.
 class UpdateCheckDriver {
@@ skipping 568 matching lines @@
     const GoogleUpdate3ClassFactory& google_update_factory) {
   if (g_google_update_factory) {
     delete g_google_update_factory;
     g_google_update_factory = nullptr;
   }
   if (!google_update_factory.is_null()) {
     g_google_update_factory =
         new GoogleUpdate3ClassFactory(google_update_factory);
   }
 }