cc: Keep tile eviction prioritization consistent with raster priorities.

We prioritize rasterization of drawing layers over non-drawing layers.
Ensure tile eviction also respects this policy.

BUG=724591
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel

Review-Url: https://codereview.chromium.org/2910303002
Cr-Commit-Position: refs/heads/master@{#476005}
5 files changed