Use DCHECKs when observing only a single notification.

chrome/browser/chromeos/policy/cloud_external_data_policy_observer.cc

 // Copyright 2013 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/chromeos/policy/cloud_external_data_policy_observer.h"
 
 #include <set>
 #include <utility>
 #include <vector>
 
@@ skipping 140 matching lines @@
 }
 
 void CloudExternalDataPolicyObserver::Init() {
   RetrieveDeviceLocalAccounts();
 }
 
 void CloudExternalDataPolicyObserver::Observe(
     int type,
     const content::NotificationSource& source,
     const content::NotificationDetails& details) {
-  if (type != chrome::NOTIFICATION_LOGIN_USER_PROFILE_PREPARED) {
-    NOTREACHED();
-    return;
-  }
+  DCHECK_EQ(chrome::NOTIFICATION_LOGIN_USER_PROFILE_PREPARED, type);
+
   Profile* profile = content::Details<Profile>(details).ptr();
-
   const user_manager::User* user =
       chromeos::ProfileHelper::Get()->GetUserByProfile(profile);
   if (!user) {
     NOTREACHED();
     return;
   }
 
   const std::string& user_id = user->email();
   if (ContainsKey(logged_in_user_observers_, user_id)) {
     NOTREACHED();
@@ skipping 123 matching lines @@
 void CloudExternalDataPolicyObserver::OnExternalDataFetched(
     const std::string& user_id,
     std::unique_ptr<std::string> data) {
   FetchWeakPtrMap::iterator it = fetch_weak_ptrs_.find(user_id);
   DCHECK(it != fetch_weak_ptrs_.end());
   fetch_weak_ptrs_.erase(it);
   delegate_->OnExternalDataFetched(policy_, user_id, std::move(data));
 }
 
 }  // namespace policy