Use DCHECKs when observing only a single notification.

chrome/browser/service_process/service_process_control.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/service_process/service_process_control.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 186 matching lines @@
   if (!channel_.get())
     return false;
   return channel_->Send(message);
 }
 
 // content::NotificationObserver implementation.
 void ServiceProcessControl::Observe(
     int type,
     const content::NotificationSource& source,
     const content::NotificationDetails& details) {
-  if (type == chrome::NOTIFICATION_UPGRADE_RECOMMENDED) {
-    Send(new ServiceMsg_UpdateAvailable);
-  }
+  DCHECK_EQ(chrome::NOTIFICATION_UPGRADE_RECOMMENDED, type);
+  Send(new ServiceMsg_UpdateAvailable);
 }
 
 void ServiceProcessControl::OnCloudPrintProxyInfo(
     const cloud_print::CloudPrintProxyInfo& proxy_info) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   UMA_HISTOGRAM_ENUMERATION("CloudPrint.ServiceEvents",
                             SERVICE_EVENT_INFO_REPLY, SERVICE_EVENT_MAX);
   if (!cloud_print_info_callback_.is_null()) {
     cloud_print_info_callback_.Run(proxy_info);
     cloud_print_info_callback_.Reset();
@@ skipping 164 matching lines @@
   if (process_.IsValid()) {
     BrowserThread::PostTask(
         BrowserThread::IO, FROM_HERE,
         base::Bind(&Launcher::DoDetectLaunched, this));
   } else {
     BrowserThread::PostTask(
         BrowserThread::UI, FROM_HERE, base::Bind(&Launcher::Notify, this));
   }
 }
 #endif  // !OS_MACOSX