Suspected CL could 
https://chromium.googlesource.com/chromium/src//+/1d5b6507ac2cbfdbb733cbefa1dbbce091b11a06
Last updated by tkent @ weeks ago , please have a look and reassign if needed.

ClusterFuzz has detected this issue as fixed in range 398017:398351.

Detailed report: https://cluster-fuzz.appspot.com/testcase?key=6488266237018112

Fuzzer: inferno_layout_test_unmodified
Job Type: linux_lsan_chrome_mp
Platform Id: linux

Crash Type: UNKNOWN READ
Crash Address: 0x000000000000
Crash State:
  blink::HTMLSelectElement::PopupUpdater::call
  blink::MutationObserver::deliver
  blink::MutationObserver::deliverMutations
  
Regressed: https://cluster-fuzz.appspot.com/revisions?job=linux_lsan_chrome_mp&range=209699:209703
Fixed: https://cluster-fuzz.appspot.com/revisions?job=linux_lsan_chrome_mp&range=398017:398351

Minimized Testcase (1.54 Kb): https://cluster-fuzz.appspot.com/download/AMIfv957hgBQqW5O98Lep8H1YCDZdcxWXXQnD_u__Q8-lZIrc9yE9xqY7dMSp3lFmKJp_W-JHOQ0AIdx0niyCwNd2GTmlO9S9cohGFeZu_VqSscNJjbyyFLPb7AUiXaUFnMToq3KE4faxw9dtGlTy4PZw_t5hlNgrA?testcase_id=6488266237018112

Additional requirements: Requires HTTP

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.

I wonder why crashes I already fixed were reported repeatedly.

Seems like this CF failure (https://cluster-fuzz.appspot.com/testcase?key=6488266237018112) is related to chrome#51.0.2704.106, so we may need a merge to M51 branch: 2704.

Thank you!

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