Page History
...
This is primarily useful in chromeless installed applications, such as those running in a native app webview or web applications where you have control of the application entry point. When people may enter your application at different points from search engine or from bookmarks you should avoid back buttons and create buttons that explicitly state where tapping them will go.
Default value
False - no back button is added to headers.
Valid values
True, False, or any valid XPath expression that returns a boolean value.