Fix typo in options2 browser_options.js

This will properly disable "Disconnect my account..." button on
ChromeOS.

cr.isChromeOs (note the last small "s", not capital "S")
returned "undefined" and thus "Disconnect..." button's
hidden attribute was always false (i.e. visible on ChromeOS).

BUG=116342
TEST=manually open chrome://settings with signed-in account and see
"Disconnect your google account" button won't appear.

Review URL: https://chromiumcodereview.appspot.com/9702051

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@126842 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/resources/options2/browser_options.js

@@ -554,7 +554,7 @@ cr.define('options', function() {
       startStopButton.disabled = syncData.managed ||
           syncData.setupInProgress;
       startStopButton.hidden =
-          syncData.setupCompleted && cr.isChromeOs;
+          syncData.setupCompleted && cr.isChromeOS;
       startStopButton.textContent =
           syncData.setupCompleted ?
               localStrings.getString('syncButtonTextStop') :