tree 200b5aa22c9738255b217772c3c7f5df2765a1dc
parent 67457275e03dc426c094dd910f771e791ecdfec2
author Riddle Hsu <riddlehsu@google.com> 1574271178 +0800
committer Tony Wickham <twickham@google.com> 1583372358 +0000

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
(cherry picked from commit 0ae61c8d2979569c5ca74593b8e4e48e825f86e2)