Use DCHECKs when observing only a single notification.

chrome/browser/ssl/ssl_error_handler.cc

 // Copyright 2014 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/ssl/ssl_error_handler.h"
 
 #include <stdint.h>
 #include <utility>
 
 #include "base/callback_helpers.h"
@@ skipping 361 matching lines @@
     RecordUMA(WWW_MISMATCH_URL_NOT_AVAILABLE);
     ShowSSLInterstitial();
   }
 }
 
 void SSLErrorHandler::Observe(
     int type,
     const content::NotificationSource& source,
     const content::NotificationDetails& details) {
 #if defined(ENABLE_CAPTIVE_PORTAL_DETECTION)
-  if (type == chrome::NOTIFICATION_CAPTIVE_PORTAL_CHECK_RESULT) {
-    timer_.Stop();
-    CaptivePortalService::Results* results =
-        content::Details<CaptivePortalService::Results>(details).ptr();
-    if (results->result == captive_portal::RESULT_BEHIND_CAPTIVE_PORTAL)
-      ShowCaptivePortalInterstitial(results->landing_url);
-    else
-      ShowSSLInterstitial();
-  }
+  DCHECK_EQ(chrome::NOTIFICATION_CAPTIVE_PORTAL_CHECK_RESULT, type);
+
+  timer_.Stop();
+  CaptivePortalService::Results* results =
+      content::Details<CaptivePortalService::Results>(details).ptr();
+  if (results->result == captive_portal::RESULT_BEHIND_CAPTIVE_PORTAL)
+    ShowCaptivePortalInterstitial(results->landing_url);
+  else
+    ShowSSLInterstitial();
 #endif
 }
 
 void SSLErrorHandler::DidStartNavigationToPendingEntry(
     const GURL& /* url */,
     content::NavigationController::ReloadType /* reload_type */) {
 // Destroy the error handler on all new navigations. This ensures that the
 // handler is properly recreated when a hanging page is navigated to an SSL
 // error, even when the tab's WebContents doesn't change.
   DeleteSSLErrorHandler();
@@ skipping 10 matching lines @@
   if (!callback_.is_null()) {
     base::ResetAndReturn(&callback_).Run(false);
   }
   if (common_name_mismatch_handler_) {
     common_name_mismatch_handler_->Cancel();
     common_name_mismatch_handler_.reset();
   }
   // Deletes |this| and also destroys the timer.
   web_contents_->RemoveUserData(UserDataKey());
 }