tree c144d5debdc96bfb3826dec18b1f932b24c16c18
parent 7a7360ad528576d560aa13fbb4e81740b2c425b2
author Craig Mautner <cmautner@google.com> 1361505658 -0800
committer Craig Mautner <cmautner@google.com> 1361505658 -0800

Update histories simultaneously.

In moveTaskToBackLocked calls that used mHistory were being made
between the times that mTaskHistory and mHistory were modified. This
caused an inconsistent state that led to Windows arranged out of
order. Updating both history stacks at the same time fixes this.

Fixes bug 8244261.

Change-Id: I9669762ad39b06ab6d401122702b74969d4dc658