MD Settings: Remove unnecessary importHtml() calls in site-settings tests.

chrome/test/data/webui/settings/usb_devices_tests.js

Index: chrome/test/data/webui/settings/usb_devices_tests.js
diff --git a/chrome/test/data/webui/settings/usb_devices_tests.js b/chrome/test/data/webui/settings/usb_devices_tests.js
index eb5ebdc504a4467d16fb1b41348ed8f138e03efd..9acf92900f68ea629f39326e4bfef6416fabc250 100644
--- a/chrome/test/data/webui/settings/usb_devices_tests.js
+++ b/chrome/test/data/webui/settings/usb_devices_tests.js
@@ -50,12 +50,6 @@ cr.define('usb_devices', function() {
         }
       ];
 
-      // Import necessary html before running suite.
-      suiteSetup(function() {
-        return PolymerTest.importHtml(
-           'chrome://md-settings/site_settings/usb_devices.html');
-      });
-
       setup(function() {
         browserProxy = new TestSiteSettingsPrefsBrowserProxy();
         settings.SiteSettingsPrefsBrowserProxyImpl.instance_ = browserProxy;