Added UI to enable debugging features on CrOS

chrome/browser/resources/chromeos/login/oobe_screen_network.js

Index: chrome/browser/resources/chromeos/login/oobe_screen_network.js
diff --git a/chrome/browser/resources/chromeos/login/oobe_screen_network.js b/chrome/browser/resources/chromeos/login/oobe_screen_network.js
index 78df29c35394a3b08d22e96ef3aca433e4608c3f..c514fb00b759abdc8273485801cdf208f3fc3d13 100644
--- a/chrome/browser/resources/chromeos/login/oobe_screen_network.js
+++ b/chrome/browser/resources/chromeos/login/oobe_screen_network.js
@@ -36,10 +36,22 @@ login.createScreen('NetworkScreen', 'connect', function() {
 
       this.dropdown_ = $('networks-list');
       cr.ui.DropDown.decorate(this.dropdown_);
+
+      $('connect-debugging-features-link').addEventListener('click',
+        this.handleDeveloperFeaturesLinkClick_.bind(this));
+      $('connect-debugging-features-link').addEventListener('keyup',
+        function(event) {
+          if (event.keyCode == 32)

[xiyuan, 2014/10/30 03:52:08]

Seems like we need a button that responds to space key rather than a link. We
used to have css to make a button looks like a link but somehow I am no longer
able to find it. :(

[zel, 2014/10/31 01:22:26]

I've just copies what we already do for accessibility link.

[xiyuan, 2014/10/31 03:36:01]

Yep, let's just keep it as is.

+            this.handleDeveloperFeaturesLinkClick_(event);
+        }
+      );
     },
 
     onBeforeShow: function(data) {
       cr.ui.DropDown.show('networks-list', true, -1);
+      this.classList.remove('connect-debugging-view');
+      if ('isDeveloperMode' in data && data['isDeveloperMode'])
+        this.classList.add('connect-debugging-view');

[xiyuan, 2014/10/30 03:52:08]

nit: this.classList.toggle('connect-debugging-view', 'isDeveloperMode' in data
&& data['isDeveloperMode']);

[zel, 2014/10/31 01:22:26]

Done.

     },
 
     onBeforeHide: function() {
@@ -84,6 +96,13 @@ login.createScreen('NetworkScreen', 'connect', function() {
     },
 
     /**
+     * Enable developer features link handler.
+     */
+    handleDeveloperFeaturesLinkClick_: function() {
+      chrome.send('toggleEnableDebuggingScreen');
+    },
+
+    /**
      * Enables/disables continue button.
      * @param {boolean} enable Should the button be enabled?
      */