Use DCHECKs when observing only a single notification.

chrome/browser/ssl/ssl_error_handler.cc

Index: chrome/browser/ssl/ssl_error_handler.cc
diff --git a/chrome/browser/ssl/ssl_error_handler.cc b/chrome/browser/ssl/ssl_error_handler.cc
index 4f58013e0632ef938a3b0f7310622822d51d0b33..0efa0e997c183f2d2b23bca99d54a2a318a409f6 100644
--- a/chrome/browser/ssl/ssl_error_handler.cc
+++ b/chrome/browser/ssl/ssl_error_handler.cc
@@ -379,15 +379,15 @@ void SSLErrorHandler::Observe(
     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
 }