The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/dc03a50c0abe027a408aae5c72f08b10d7fbe584

commit dc03a50c0abe027a408aae5c72f08b10d7fbe584
Author: suzyh <suzyh@chromium.org>
Date: Thu Apr 20 00:53:35 2017

Fix step timing outside range [0,1]

With inputs outside the range [0,1], the steps timing function does not
match the behaviour described in
https://www.w3.org/TR/css-timing-1/#step-timing-functions,
as demonstrated by the failing
LayoutTests/external/wpt/css-timing-1/step-timing-functions-output.html.
This patch changes the step timing implementation to match the specced
algorithm.

BUG= 712918 
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel

Review-Url: https://codereview.chromium.org/2830553002
Cr-Commit-Position: refs/heads/master@{#465835}

[modify] https://crrev.com/dc03a50c0abe027a408aae5c72f08b10d7fbe584/cc/animation/keyframed_animation_curve_unittest.cc
[modify] https://crrev.com/dc03a50c0abe027a408aae5c72f08b10d7fbe584/cc/animation/timing_function.cc
[delete] https://crrev.com/616af64093de539709fe6be5085029a42e58fe2d/third_party/WebKit/LayoutTests/external/wpt/css-timing-1/step-timing-functions-output-expected.txt
[modify] https://crrev.com/dc03a50c0abe027a408aae5c72f08b10d7fbe584/third_party/WebKit/Source/platform/animation/TimingFunctionTest.cpp