Don't skip displaying zoom levels for host-only zoom changes.

A previous change to skip displaying zoom levels for host and scheme
zoom changes caused host-only zoom changes to be skipped due to surprise
case fallthrough. This adds a break so the correct zoom settings are
displayed.

BUG=454254

Review URL: https://codereview.chromium.org/879333003

Cr-Commit-Position: refs/heads/master@{#314275}

chrome/browser/ui/webui/options/content_settings_handler.cc

@@ -1060,6 +1060,7 @@ void ContentSettingsHandler::UpdateZoomLevelsExceptionsView() {
               l10n_util::GetStringUTF8(IDS_ZOOMLEVELS_CHROME_ERROR_PAGES_LABEL);
         }
         exception->SetString(kOrigin, host);
+        break;
       }
       case content::HostZoomMap::ZOOM_CHANGED_FOR_SCHEME_AND_HOST:
         // These are not stored in preferences and get cleared on next browser