Use DCHECKs when observing only a single notification.

chrome/browser/download/chrome_download_manager_delegate.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/download/chrome_download_manager_delegate.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 694 matching lines @@
   state->CompleteDownload();
 }
 #endif  // FULL_SAFE_BROWSING
 
 // content::NotificationObserver implementation.
 void ChromeDownloadManagerDelegate::Observe(
     int type,
     const content::NotificationSource& source,
     const content::NotificationDetails& details) {
 #if defined(ENABLE_EXTENSIONS)
-  DCHECK(type == extensions::NOTIFICATION_CRX_INSTALLER_DONE);
+  DCHECK_EQ(extensions::NOTIFICATION_CRX_INSTALLER_DONE, type);
 
   registrar_.Remove(this, extensions::NOTIFICATION_CRX_INSTALLER_DONE, source);
 
   scoped_refptr<extensions::CrxInstaller> installer =
       content::Source<extensions::CrxInstaller>(source).ptr();
   content::DownloadOpenDelayedCallback callback =
       crx_installers_[installer.get()];
   crx_installers_.erase(installer.get());
   callback.Run(installer->did_handle_successfully());
 #endif
@@ skipping 46 matching lines @@
       path.MatchesExtension(FILE_PATH_LITERAL(".xht")) ||
       path.MatchesExtension(FILE_PATH_LITERAL(".xhtm")) ||
       path.MatchesExtension(FILE_PATH_LITERAL(".xhtml")) ||
       path.MatchesExtension(FILE_PATH_LITERAL(".xsl")) ||
       path.MatchesExtension(FILE_PATH_LITERAL(".xslt"))) {
     return true;
   }
 #endif
   return false;
 }