All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=792544

(For debugging:) Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?sid=c59ab102c19c12a74535e20360ccb7ddda82b8a5dcfd89f733470e86ac3b0a91


Bot(s) for this bug's original alert(s):

win-high-dpi

📍 Pinpoint job started.
https://pinpoint-dot-chromeperf.appspot.com/job/11db0194040000

📍 Found a significant difference after 1 commit.
https://pinpoint-dot-chromeperf.appspot.com/job/11db0194040000

[PE] Turn on half-width tiles for all platforms and devices.
By chrishtr@chromium.org · Tue Dec 05 01:51:58 2017
chromium @ a3e4477c29d087d3708dbcb4dc5a90985c2b45e3

Understanding performance regressions:
  http://g.co/ChromePerformanceRegressions

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/a78535de3d2153706ef21bf918333353e59ea496

commit a78535de3d2153706ef21bf918333353e59ea496
Author: Eric Karl <ericrk@chromium.org>
Date: Wed Jan 17 23:49:37 2018

Move tile half-width optimization after all rounding

Currently, we determine whether to use half-width tiles before final
tile-size rounding. In rare cases, this results in halving a tile
that would have successfully held all content after rounding.

This CL avoids these cases by handling the half-width after rounding.

Bug:  792544 ,  792457 
Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.android:android_optional_gpu_tests_rel
Change-Id: I428076de01268980495507a93339fae7d6ab0878
Reviewed-on: https://chromium-review.googlesource.com/871698
Reviewed-by: vmpstr <vmpstr@chromium.org>
Commit-Queue: Eric Karl <ericrk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#529952}
[modify] https://crrev.com/a78535de3d2153706ef21bf918333353e59ea496/cc/layers/picture_layer_impl.cc
[modify] https://crrev.com/a78535de3d2153706ef21bf918333353e59ea496/cc/layers/picture_layer_impl_unittest.cc