Enable tests related to the extensions web ui that were flaky.

chrome/browser/resources/extensions/extensions.js

Index: chrome/browser/resources/extensions/extensions.js
diff --git a/chrome/browser/resources/extensions/extensions.js b/chrome/browser/resources/extensions/extensions.js
index e094312bba88eb769323613216a95ca2a3c30158..b160c9385144d2ffc28f8a8dddfb2c4c8715e561 100644
--- a/chrome/browser/resources/extensions/extensions.js
+++ b/chrome/browser/resources/extensions/extensions.js
@@ -345,6 +345,9 @@ cr.define('extensions', function() {
       window.requestAnimationFrame(function() {
         devControls.style.height = !showDevControls ? '' :
             buttons.offsetHeight + 'px';
+
+        if (this.testingDeveloperModeCallback)

[not at google - send to devlin, 2015/04/29 22:03:31]

Where is this defined?

[hcarmona, 2015/04/30 18:42:00]

Defined now.

+          this.testingDeveloperModeCallback();
       }.bind(this));
     },
   };