Bug 981566 - [settings] add marionette test for device information - You...

...r Privacy
developMenu may be or not enabled by default. It depends on whether it is engineering build or production build.
I think we should ...
''' 
var isDevelopMenuDefaultEnabled = deviceInfoPanel.isDevelopMenuEnabled;
deviceInfoPanel.enableDevelopMenu(); // suggest to rename it as deviceInfoPanel.triggerDevelopMenu();
assert.notEqual(deviceInfoPanel.isDevelopMenuEnabled, isDevelopMenuDefaultEnabled);
deviceInfoPanel.goBackToRootPanel();
assert.notEqual(deviceInfoPanel.isDeveloperMenuItemVisible, isDevelopMenuDefaultEnabled);
'''