Predator and CL could not provide any possible suspects.
Using Code Search for the file, "textiterator.cpp" assigning to the concern owner from GIT Blame.

Suspecting Commit#
https://chromium.googlesource.com/chromium/src/+/c8070f461957f5f2aaaf41147538ebe811b4abce

@xiaochengh -- Could you please look into it issue, kindly re-assign if this not related your changes.
Thank You.

Hit DCHECK in CompositeEditCommand::RemoveNodeAndPruneAncestors():

CompositeEditCommand.cpp(421) Check failed: node != exclude_node (TEXTAREA class="CLASS1" (editable) vs. TEXTAREA class="CLASS1" (editable))

DOM tree at DCHECK hit site:

#document (editable)
	HTML (editable)
		HEAD (editable)
			SCRIPT (editable)
			#text "\n"
			STYLE (editable)
			#text "\n"
		BODY (editable)
			DL (editable)
				#text "\n"
				UL (editable)
*					TEXTAREA class="CLASS1" (editable)
						#shadow-root
							DIV id="inner-editor" (editable)
								#text "<dd"
						#text "<dd"
				BR (editable)

Automatically applying components based on information from OWNERS files. If this seems incorrect, please apply the Test-Predator-Wrong-Components label.

Lower to Pri-3 since real world usage of InsertUnorderedList crashes with unusual HTML is low.

Automatically adding ccs based on suspected regression changelists:

https://chromium.googlesource.com/chromium/src/+/7c02de6787d8499ce5e8be12063db19daeace77e (Revert "Import web-platform-tests/editing/." by grt@chromium.org)https://chromium.googlesource.com/chromium/src/+/2211504ac2b999a125b2215ce7f6be9e50878fea (Make PositionIterator to skip contents of INPUT/SELECT/TEXTAREA by yosin@chromium.org)
If this is incorrect, please apply the Test-Predator-Wrong-CLs label.

Automatically adding ccs based on suspected regression changelists:

https://chromium.googlesource.com/chromium/src/+/7c02de6787d8499ce5e8be12063db19daeace77e (Revert "Import web-platform-tests/editing/." by grt@chromium.org)https://chromium.googlesource.com/chromium/src/+/2211504ac2b999a125b2215ce7f6be9e50878fea (Make PositionIterator to skip contents of INPUT/SELECT/TEXTAREA by yosin@chromium.org)
If this is incorrect, please apply the Test-Predator-Wrong-CLs label.

Automatically adding ccs based on suspected regression changelists:

https://chromium.googlesource.com/chromium/src/+/7c02de6787d8499ce5e8be12063db19daeace77e (Revert "Import web-platform-tests/editing/." by grt@chromium.org)https://chromium.googlesource.com/chromium/src/+/2211504ac2b999a125b2215ce7f6be9e50878fea (Make PositionIterator to skip contents of INPUT/SELECT/TEXTAREA by yosin@chromium.org)
If this is incorrect, please apply the Test-Predator-Wrong-CLs label.

Automatically adding ccs based on suspected regression changelists:

https://chromium.googlesource.com/chromium/src/+/7c02de6787d8499ce5e8be12063db19daeace77e (Revert "Import web-platform-tests/editing/." by grt@chromium.org)https://chromium.googlesource.com/chromium/src/+/2211504ac2b999a125b2215ce7f6be9e50878fea (Make PositionIterator to skip contents of INPUT/SELECT/TEXTAREA by yosin@chromium.org)
If this is incorrect, please apply the Test-Predator-Wrong-CLs label.

Automatically adding ccs based on suspected regression changelists:

https://chromium.googlesource.com/chromium/src/+/7c02de6787d8499ce5e8be12063db19daeace77e (Revert "Import web-platform-tests/editing/." by grt@chromium.org)https://chromium.googlesource.com/chromium/src/+/2211504ac2b999a125b2215ce7f6be9e50878fea (Make PositionIterator to skip contents of INPUT/SELECT/TEXTAREA by yosin@chromium.org)
If this is incorrect, please apply the Test-Predator-Wrong-CLs label.

Automatically adding ccs based on suspected regression changelists:

https://chromium.googlesource.com/chromium/src/+/7c02de6787d8499ce5e8be12063db19daeace77e (Revert "Import web-platform-tests/editing/." by grt@chromium.org)https://chromium.googlesource.com/chromium/src/+/2211504ac2b999a125b2215ce7f6be9e50878fea (Make PositionIterator to skip contents of INPUT/SELECT/TEXTAREA by yosin@chromium.org)
If this is incorrect, please apply the Test-Predator-Wrong-CLs label.

Please ignore the Test-Predator-Auto-CC comment spam above, there was a bug in our script that caused it to create same comment multiple times and also didn't add ccs properly. 

ClusterFuzz has detected this issue as fixed in range 521421:521451.

Detailed report: https://clusterfuzz.com/testcase?key=5579750264537088

Fuzzer: bj_broddelwerk
Job Type: windows_asan_chrome
Platform Id: windows

Crash Type: Null-dereference
Crash Address: 0x00000003
Crash State:
  blink::TextIteratorAlgorithm<blink::EditingAlgorithm<blink::NodeTraversal> >::Te
  blink::TextIteratorAlgorithm<blink::EditingAlgorithm<blink::NodeTraversal> >::Ra
  blink::CompositeEditCommand::MoveParagraphs
  
Sanitizer: address (ASAN)

Regressed: https://clusterfuzz.com/revisions?job=windows_asan_chrome&range=454233:454289
Fixed: https://clusterfuzz.com/revisions?job=windows_asan_chrome&range=521421:521451

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=5579750264537088

See https://github.com/google/clusterfuzz-tools 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 5579750264537088 is verified as fixed, so closing issue as verified.

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