extensions: clean up hiding/showing of developer controls.

chrome/browser/ui/webui/extensions/extension_settings_browsertest.js

Index: chrome/browser/ui/webui/extensions/extension_settings_browsertest.js
diff --git a/chrome/browser/ui/webui/extensions/extension_settings_browsertest.js b/chrome/browser/ui/webui/extensions/extension_settings_browsertest.js
index 3ae8df0fd0ec945bc05e2eb511eab26a2903e43e..80eb706c7af49317b0f2a49431a737b4a4821556 100644
--- a/chrome/browser/ui/webui/extensions/extension_settings_browsertest.js
+++ b/chrome/browser/ui/webui/extensions/extension_settings_browsertest.js
@@ -74,22 +74,22 @@ AsyncExtensionSettingsWebUITest.prototype = {
 };
 
 TEST_F('AsyncExtensionSettingsWebUITest', 'testDeveloperModeA11y', function() {
-  var devControl = $('dev-controls');
+  var devControls = $('dev-controls');
 
   // Make sure developer controls are hidden before checkbox is clicked.
-  assertTrue(devControl.hidden);
+  assertEquals(0, devControls.offsetHeight);
   $('toggle-dev-on').click();
 
   document.addEventListener('webkitTransitionEnd', function f(e) {
-    if (e.target == devControl) {
+    if (e.target == devControls) {
       // Make sure developer controls are not hidden after checkbox is clicked.
-      assertFalse(devControl.hidden);
+      assertGT(devControls.offsetHeight, 0);
 
       document.removeEventListener(f, 'webkitTransitionEnd');
       testDone();
     }
   });
-  ensureTransitionEndEvent(devControl, 4000);
+  ensureTransitionEndEvent(devControls, 4000);
 });
 
 /**