Use DCHECKs when observing only a single notification.

chrome/browser/printing/print_job_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/printing/print_job_manager.h"
 
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/printing/print_job.h"
 #include "chrome/browser/printing/printer_query.h"
 #include "content/public/browser/browser_thread.h"
@@ skipping 94 matching lines @@
     if (wait_for_finish)
       (*job)->FlushJob(base::TimeDelta::FromMinutes(2));
     (*job)->Stop();
   }
 }
 
 void PrintJobManager::Observe(int type,
                               const content::NotificationSource& source,
                               const content::NotificationDetails& details) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
-  switch (type) {
-    case chrome::NOTIFICATION_PRINT_JOB_EVENT: {
-      OnPrintJobEvent(content::Source<PrintJob>(source).ptr(),
-                      *content::Details<JobEventDetails>(details).ptr());
-      break;
-    }
-    default: {
-      NOTREACHED();
-      break;
-    }
-  }
+  DCHECK_EQ(chrome::NOTIFICATION_PRINT_JOB_EVENT, type);
+
+  OnPrintJobEvent(content::Source<PrintJob>(source).ptr(),
+                  *content::Details<JobEventDetails>(details).ptr());
 }
 
 void PrintJobManager::OnPrintJobEvent(
     PrintJob* print_job,
     const JobEventDetails& event_details) {
   switch (event_details.type()) {
     case JobEventDetails::NEW_DOC: {
       DCHECK(current_jobs_.end() == current_jobs_.find(print_job));
       // Causes a AddRef().
       current_jobs_.insert(print_job);
@@ skipping 19 matching lines @@
       break;
     }
     default: {
       NOTREACHED();
       break;
     }
   }
 }
 
 }  // namespace printing