Change GPU Tile rounding to 32

Rounding to 64 was done to match SW, but this leads to android
memory regressions. Use 32 instead, which still fixes the Core
Animation issue, but doesn’t regress memory as much.

BUG=632274
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_precise_blink_rel

Review-Url: https://codereview.chromium.org/2258343002
Cr-Commit-Position: refs/heads/master@{#413310}
3 files changed