Update the last frames in relayout window

The frames are computed in relayout and the client also uses
it as the last state. It is unnecessary to request redraw by
a false alarm frame changes.

Fix: 144585233
Test: atest DisplaySizeTest
Test: 1. Launch an activity that doesn't handle density change.
      2. Change density by shell command "wm density $value".
      3. Check there won't be a black screen.

Change-Id: Ia9dbda66506ef11e5cbe811f635031756803742b