commit 0ae61c8d2979569c5ca74593b8e4e48e825f86e2
author Riddle Hsu <riddlehsu@google.com> Thu Nov 21 01:32:58 2019 +0800
committer Riddle Hsu <riddlehsu@google.com> Fri Dec 13 16:55:54 2019 +0800
tree d8dcfb70346087b7e15754a0bd9e8b4613631342
parent e8dc428a0229261c383a5939f22b6832d2f72a6f

Invalidate snapshot of home if its UI is changed

Snapshot may be enabled for home task when turning off
screen. If home UI has changed after screen off, the
snapshot should not be used to avoid ugly visual effect.

Bug: 140811348
Test: Lock/unlock device while home is on top with 4 cases:
      1. All apps is shown.
      2. Overview is shown.
      3. Options menu is shown.
      4. Quick search bar is active.
      The expected result should be no starting window
      when unlocking because the snapshot is dropped.

Change-Id: I4bd9926b6f9332ac16b1b3a25ffdd44706015a33