Change the display list interest rect size to 4000px instead of 8000px.

Change the display list interest rect size to 4000px instead of 8000px.

8000px has been the value for a long time. Reducing it would help slimming
paint performance.

BUG=526306
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Committed: https://crrev.com/0f7133512f98bc2e2dc10dff33466652ad44025e
Cr-Commit-Position: refs/heads/master@{#346421}

[chrishtr, 2015-08-28 23:08:34]

chrishtr@chromium.org changed reviewers:
+ enne@chromium.org

[chrishtr, 2015-08-28 23:09:01]

We should try this on M46 & M47 and observe UMA & other stats.

[enne (OOO), 2015-08-31 17:15:18]

lgtm

[chrishtr, 2015-08-31 17:18:43]

The CQ bit was checked by chrishtr@chromium.org

[commit-bot: I haz the power, 2015-08-31 17:19:16]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1312423005/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1312423005/1

[commit-bot: I haz the power, 2015-08-31 18:25:34]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-08-31 18:26:01]

Patchset 1 (id:??) landed as
https://crrev.com/0f7133512f98bc2e2dc10dff33466652ad44025e
Cr-Commit-Position: refs/heads/master@{#346421}