Assigning to the concern owner from Find it. Below are the results --
The result is a list of CLs that change the crashed files. 

Author: reed
Project: chromium
Changelist: https://chromium.googlesource.com/chromium/src/+/e9559d0c2c6dd8408d408b795c86f3ff7dfc178e
Time: Mon Dec 05 22:21:50 2016
File BaseRenderingContext2D.cpp is changed in this cl (and is part of stack frame #1, "blink::BaseRenderingContext2D::computeDirtyRect"; frame #3, "blink::BaseRenderingContext2D::fillRect")
Minimum distance from crash line to modified line: 57. (file: BaseRenderingContext2D.cpp, crashed on: 685, modified: 742).

@reed -- Could you please look into the issue, kindly re-assign if this is not related to your changes.
Thank You.

ClusterFuzz has detected this issue as fixed in range 440242:440280.

Detailed report: https://cluster-fuzz.appspot.com/testcase?key=5678249503096832

Fuzzer: inferno_twister
Job Type: linux_ubsan_chrome
Platform Id: linux

Crash Type: Float-cast-overflow
Crash Address: 
Crash State:
  SkRect::roundOut
  blink::BaseRenderingContext2D::computeDirtyRect
  draw<
  
Regressed: https://cluster-fuzz.appspot.com/revisions?job=linux_ubsan_chrome&range=435261:438085
Fixed: https://cluster-fuzz.appspot.com/revisions?job=linux_ubsan_chrome&range=440242:440280

Minimized Testcase (1.60 Kb): https://cluster-fuzz.appspot.com/download/AMIfv946P0_2uCsNEHB7Ag2OfEvKbJe54hEo5uKBJAX3Z_zr-PaXn6UB3odeUsxaztr9vE-CwfBQftFVJqL3PGx1ywJJ0AMH5URFnnp21ac8eAF54WofWTXvueVXYxtxCTuPkvLqZLXj5QcIlmBW4F9bG_dmgih5pw?testcase_id=5678249503096832

See https://dev.chromium.org/Home/chromium-security/bugs/reproducing-clusterfuzz-bugs for more information.

If you suspect that the result above is incorrect, try re-doing that job on the test case report page.

ClusterFuzz testcase 5678249503096832 is verified as fixed, so closing issue.

If this is incorrect, please add ClusterFuzz-Wrong label and re-open the issue.