Use DCHECKs when observing only a single notification.

chrome/browser/printing/print_job.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/printing/print_job.h"
 
 #include <memory>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 74 matching lines @@
 
   // Don't forget to register to our own messages.
   registrar_.Add(this, chrome::NOTIFICATION_PRINT_JOB_EVENT,
                  content::Source<PrintJob>(this));
 }
 
 void PrintJob::Observe(int type,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) {
   DCHECK(RunsTasksOnCurrentThread());
-  switch (type) {
-    case chrome::NOTIFICATION_PRINT_JOB_EVENT: {
-      OnNotifyPrintJobEvent(*content::Details<JobEventDetails>(details).ptr());
-      break;
-    }
-    default: {
-      break;
-    }
-  }
+  DCHECK_EQ(chrome::NOTIFICATION_PRINT_JOB_EVENT, type);
+
+  OnNotifyPrintJobEvent(*content::Details<JobEventDetails>(details).ptr());
 }
 
 void PrintJob::GetSettingsDone(const PrintSettings& new_settings,
                                PrintingContext::Result result) {
   NOTREACHED();
 }
 
 PrintJobWorker* PrintJob::DetachWorker(PrintJobWorkerOwner* new_owner) {
   NOTREACHED();
   return NULL;
@@ skipping 341 matching lines @@
 }
 
 JobEventDetails::~JobEventDetails() {
 }
 
 PrintedDocument* JobEventDetails::document() const { return document_.get(); }
 
 PrintedPage* JobEventDetails::page() const { return page_.get(); }
 
 }  // namespace printing