Bug 1042319 - [Gallery] WIP patch of update gallery edit UI and visuals

I don't like the name of this method or of its argument.  'flag' is too generic a name. I'd prefer something like 'show' so I that I know that if true is passed then the method will be showing something, and if false is passed it will be hiding something.  But then there is redundancy with the "show" in the method name.

Given that the body of the method is a big if/else, consider breaking this into two methods: showEditModeView and hideEditModeView.

Even better, though, would be if you could integrate this code into setEditTool(). Pass null to setEditTool() to revert back to the main edit screen.