Use DCHECKs when observing only a single notification.

chrome/browser/background/background_mode_manager.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/background/background_mode_manager.h"
 
 #include <stddef.h>
 #include <algorithm>
 #include <string>
 #include <utility>
@@ skipping 445 matching lines @@
   std::vector<base::string16> new_client_names;
   OnClientsChanged(profile, new_client_names);
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 //  BackgroundModeManager, content::NotificationObserver overrides
 void BackgroundModeManager::Observe(
     int type,
     const content::NotificationSource& source,
     const content::NotificationDetails& details) {
-  switch (type) {
-    case chrome::NOTIFICATION_APP_TERMINATING:
-      // Make sure we aren't still keeping the app alive (only happens if we
-      // don't receive an EXTENSIONS_READY notification for some reason).
-      ReleaseStartupKeepAlive();
-      // Performing an explicit shutdown, so exit background mode (does nothing
-      // if we aren't in background mode currently).
-      EndBackgroundMode();
-      // Shutting down, so don't listen for any more notifications so we don't
-      // try to re-enter/exit background mode again.
-      registrar_.RemoveAll();
-      for (const auto& it : background_mode_data_)
-        it.second->applications_->RemoveObserver(this);
-      break;
-    default:
-      NOTREACHED();
-      break;
-  }
+  DCHECK_EQ(chrome::NOTIFICATION_APP_TERMINATING, type);
+
+  // Make sure we aren't still keeping the app alive (only happens if we
+  // don't receive an EXTENSIONS_READY notification for some reason).
+  ReleaseStartupKeepAlive();
+  // Performing an explicit shutdown, so exit background mode (does nothing
+  // if we aren't in background mode currently).
+  EndBackgroundMode();
+  // Shutting down, so don't listen for any more notifications so we don't
+  // try to re-enter/exit background mode again.
+  registrar_.RemoveAll();
+  for (const auto& it : background_mode_data_)
+    it.second->applications_->RemoveObserver(this);
 }
 
 void BackgroundModeManager::OnExtensionsReady(Profile* profile) {
   BackgroundModeManager::BackgroundModeData* bmd =
       GetBackgroundModeData(profile);
   if (bmd) {
     UMA_HISTOGRAM_COUNTS_100("BackgroundMode.BackgroundApplicationsCount",
         bmd->applications_->size());
   }
   // Extensions are loaded, so we don't need to manually keep the browser
@@ skipping 535 matching lines @@
     }
   }
   return profile_it;
 }
 
 bool BackgroundModeManager::IsBackgroundModePrefEnabled() const {
   PrefService* service = g_browser_process->local_state();
   DCHECK(service);
   return service->GetBoolean(prefs::kBackgroundModeEnabled);
 }