tree cdd2df74f6544368f6f75e47c5ed802279953c55
parent ad217b68f8bfc993984fb0ceea4bae149bc46157
author Filip Gruszczynski <gruszczy@google.com> 1450235829 -0800
committer Filip Gruszczynski <gruszczy@google.com> 1450371350 -0800

Refactor and improve window layering.

This CL moves layer calculation into a separate class, so the whole
logic can be encapsulated. It also extracts special cases from the
general loop and instead applies them at the end. This simplifies the
logic in the main algorithm and makes it clearer what needs to happen
for special cases.

Bug: 26144888

Change-Id: I87347bf0198bd0d3cd09e4231b4652ab979f2456