Make using WebContentsUserData simpler.

chrome/browser/plugins/plugin_observer.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/plugins/plugin_observer.h"
 
 #include "base/auto_reset.h"
 #include "base/bind.h"
 #include "base/stl_util.h"
 #include "base/utf_string_conversions.h"
@@ skipping 28 matching lines @@
 
 #if defined(OS_WIN)
 #include "base/win/metro.h"
 #endif
 
 using content::OpenURLParams;
 using content::PluginService;
 using content::Referrer;
 using content::WebContents;
 
-int PluginObserver::kUserDataKey;
+DEFINE_WEB_CONTENTS_USER_DATA_KEY(PluginObserver)
 
 namespace {
 
 #if defined(ENABLE_PLUGIN_INSTALLATION)
 
 // ConfirmInstallDialogDelegate ------------------------------------------------
 
 class ConfirmInstallDialogDelegate : public TabModalConfirmDialogDelegate,
                                      public WeakPluginInstallerObserver {
  public:
@@ skipping 288 matching lines @@
   InfoBarTabHelper* infobar_helper = tab_contents->infobar_tab_helper();
   infobar_helper->AddInfoBar(new SimpleAlertInfoBarDelegate(
       infobar_helper,
       &ResourceBundle::GetSharedInstance().GetNativeImageNamed(
           IDR_INFOBAR_PLUGIN_CRASHED),
       l10n_util::GetStringFUTF16(IDS_PLUGIN_INITIALIZATION_ERROR_PROMPT,
                                  plugin_name),
       true  /* auto_expire */));
 }