Dump more info for View when IMM#DEBUG is true.

This is a preparation CL to fix Bug 27858665.  In order to debug issues
like this, we want to record following information about View.
 - Whether the View is focused or not.
 - Whether the Window to which the View belongs is focused or not.
 - Whether the View belongs to a Window or not.

This CL has no impact on production build where IMM#DEBUG is false.

Bug: 18920212
Change-Id: I06bcd5e42d55f96a9e916eb34ed7785cfe14c96f