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

Author: szager
Project: chromium
Changelist: https://chromium.googlesource.com/chromium/src/+/3520351e84d8d16b06d3f09a109f1296ec620c23
Time: Tue Dec 13 04:17:07 2016
Lines 230-238, 245-249, 255-269, 278 of file IntersectionObserver.cpp which potentially caused crash are changed in this cl (frame #2, "blink::IntersectionObserver::trackingDocument"). 

Files Element.cpp, ElementIntersectionObserverData.cpp are changed in this cl (and is part of stack frame #4, "blink::Element::insertedInto")
Minimum distance from crash line to modified line: 0. (file: IntersectionObserver.cpp, crashed on: 256, modified: 256).

@szager -- 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 441524:442831.

Detailed report: https://cluster-fuzz.appspot.com/testcase?key=5514807207002112

Fuzzer: inferno_twister
Job Type: linux_asan_chrome_media
Platform Id: linux

Crash Type: UNKNOWN READ
Crash Address: 0x000000000038
Crash State:
  blink::LocalFrame::document
  blink::IntersectionObserver::trackingDocument
  blink::ElementIntersectionObserverData::activateValidIntersectionObservers
  
Sanitizer: address (ASAN)

Regressed: https://cluster-fuzz.appspot.com/revisions?job=linux_asan_chrome_media&range=437986:438085
Fixed: https://cluster-fuzz.appspot.com/revisions?job=linux_asan_chrome_media&range=441524:442831

Minimized Testcase (0.36 Kb): https://cluster-fuzz.appspot.com/download/AMIfv95NlfFysW_crsZRUWD-DjSuToBsm9HzrJrV7aj03xDPJT0mEuddI8mK1xyALWvR9Rb1Dz669EysiQMDqJ14VanIGNxiy_pDiOd_ImfGzbdhHyA5onFBn_TEIbdfU9kK8iKcPJBfm3BEx_QUguSE0KB7jD7jTg?testcase_id=5514807207002112

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 5514807207002112 is verified as fixed, so closing issue.

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