Predator and CL did not provide any possible suspects.
Using Code Search for the file, "messaging_bindings.cc" assigning to the concern owner.
Suspecting Commit#
https://chromium.googlesource.com/chromium/src/+/5e65e3a4fbb5d4815760fc9b31f3bb5fb81bfbc9

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

It regressed May 2016 according to CF so I don't think it's my CL from Mar 2017. Or did I misunderstand #c2?

Adding Extensions to Components for triage.

Assigning to Devlin, suspecting https://codereview.chromium.org/1960903002.

ClusterFuzz has detected this issue as fixed in range 476474:476520.

Detailed report: https://clusterfuzz.com/testcase?key=4615808288555008

Fuzzer: inferno_layout_test_unmodified
Job Type: linux_ubsan_vptr_chrome
Platform Id: linux

Crash Type: CHECK failure
Crash Address: 
Crash State:
  args[0]->IsString() in messaging_bindings.cc
  extensions::MessagingBindings::OpenChannelToExtension
  extensions::ObjectBackedNativeHandler::Router
  
Sanitizer: undefined (UBSAN)

Regressed: https://clusterfuzz.com/revisions?job=linux_ubsan_vptr_chrome&range=392426:392516
Fixed: https://clusterfuzz.com/revisions?job=linux_ubsan_vptr_chrome&range=476474:476520

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=4615808288555008


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 4615808288555008 is verified as fixed, so closing issue.

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