Revert "Revert "Display debug menu by default""

This reverts commit 72a20c96c654e741b522c9e0ffe46db70477d3eb.
Browser: add valid missing fragments (fixes FC)

WebsiteSettingsFragment and DebugPreferencesFragment are also valid
fragments.

Change-Id: I4e945a3b9de62879afcc621fb97811e75ca53cb1
Add back browser history page.

Not sure why it was removed, but it seems to work just fine.

Change-Id: I6d76928182a53ca57d080394823d35d66e0ba987