The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/ac21de591dc92f7b4cae71e5a4afd62738344a5e

commit ac21de591dc92f7b4cae71e5a4afd62738344a5e
Author: alph <alph@chromium.org>
Date: Sat Jan 28 03:01:35 2017

DevTools: Turn pie chart into a donut chart.

BUG= 685904 

Review-Url: https://codereview.chromium.org/2664463002
Cr-Commit-Position: refs/heads/master@{#446892}

[modify] https://crrev.com/ac21de591dc92f7b4cae71e5a4afd62738344a5e/third_party/WebKit/Source/devtools/front_end/perf_ui/PieChart.js
[modify] https://crrev.com/ac21de591dc92f7b4cae71e5a4afd62738344a5e/third_party/WebKit/Source/devtools/front_end/timeline/TimelineUIUtils.js