Maybe fix issue #3358322: Status and nav bar died while watching youtube

Or at least make it better.  Now if we get a failure locking the surface,
we mark to do a full relayout pass later to try to get a new good surface.

Also fix some bugs in how activity manager was classifying processes for
their OOM adjustment to make better choices in what to kill.

Change-Id: I8e4aa86744211ba7693f9828291d8bbf2698274f