Fix sync settings metric

Metric exists but is spelled wrong in JS.

R=tim@chromium.org,estade@chromium.org

Review URL: https://codereview.chromium.org/572113002

Cr-Commit-Position: refs/heads/master@{#296578}

chrome/browser/resources/sync_setup_overlay.js

@@ -815,7 +815,7 @@ cr.define('options', function() {
      */
     showSetupUI_: function() {
       chrome.send('SyncSetupShowSetupUI');
-      chrome.send('coreOptionsUserMetricsAction', ['Options_SyncShowAdvanced']);
+      chrome.send('coreOptionsUserMetricsAction', ['Options_ShowSyncAdvanced']);
     },
 
     /**