About page should not automatically trigger OS updates

chrome/browser/resources/help/help_page.js

Index: chrome/browser/resources/help/help_page.js
diff --git a/chrome/browser/resources/help/help_page.js b/chrome/browser/resources/help/help_page.js
index d7cf0b78c51240c1c9fe4ae1524c8650007fcc90..1e8a3c18cb2f9e1e02dad4b023b905b11990910c 100644
--- a/chrome/browser/resources/help/help_page.js
+++ b/chrome/browser/resources/help/help_page.js
@@ -107,6 +107,13 @@ cr.define('help', function() {
       }
 
       if (cr.isChromeOS) {
+        // Add event listener for the check for and apply updates button.
+        this.maybeSetOnClick_($('request-update'), function() {
+          self.setUpdateStatus_('checking');
+          $('request-update').disabled = true;
+          chrome.send('requestUpdate');
+        });
+
         // Add event listener for the close button when shown as an overlay.
         if ($('about-done')) {
           $('about-done').addEventListener('click', function() {
@@ -276,12 +283,33 @@ cr.define('help', function() {
         $('relaunch-and-powerwash').hidden = relaunchAndPowerwashHidden;
       }
 
+      if (cr.isChromeOS) {
+        // Only enable the update button if it hasn't been used yet or the
+        // status isn't 'updated'.
+        if (!$('request-update').disabled || status != 'updated') {
+          // Disable the button if an update is already in progress.
+          $('request-update').disabled =
+            ['checking', 'updating', 'nearly_updated'].indexOf(status) > -1;
+        }
+      }
+
       var container = $('update-status-container');
       if (container) {
         container.hidden = status == 'disabled';
         $('relaunch').hidden =
             (status != 'nearly_updated') || !relaunchAndPowerwashHidden;
 
+        if (cr.isChromeOS) {
+          // Hide the status container if we haven't checked for updates yet.

[deymo, 2014/08/19 05:09:12]

This comment isn't quite accurate. We want to show the status of the current
update even if we didn't initiate it. Example:

Check for update, update is in progress (i.e. 20% done), refresh page --> update
should show progress.

Also, if you open this page to see if there's an update in progress you should
see that. It looks like the code is right but the comment is not.

[michaelpg, 2014/08/19 05:20:02]

I agree -- this is the desired behavior and what the code does. I'll update the
comment.

+          if (status == 'updated' && !$('request-update').disabled)
+            container.hidden = true;
+
+          // Hide the request update button if auto-updating is disabled or
+          // a relaunch button is showing.
+          $('request-update').hidden = status == 'disabled' ||
+            !$('relaunch').hidden || !relaunchAndPowerwashHidden;
+        }
+
         if (!cr.isMac)
           $('update-percentage').hidden = status != 'updating';
       }