Unable to find the possible suspect using Predator, CL and Code Search.Hence untriaging this issue, Could some one please look into the issue.

Thank You.

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

Reproduces for me.

With debug builds, before getting to Element::Shadow, the testcase hits
DCHECK in ContainerNode.cpp.

[1:1:1012/185438.329425:96700605070:FATAL:ContainerNode.cpp(314)] Check failed: !target_node->parentNode(). 
#0 0x7fd7659c4dbd base::debug::StackTrace::StackTrace()
#1 0x7fd7659c31ec base::debug::StackTrace::StackTrace()
#2 0x7fd765a49f7a logging::LogMessage::~LogMessage()
#3 0x7fd75daa2f36 blink::ContainerNode::InsertNodeVector<>()
#4 0x7fd75da9b437 blink::ContainerNode::AppendChild()
#5 0x7fd75dba41ea blink::Node::appendChild()
#6 0x7fd75ece77c6 blink::NodeV8Internal::appendChildMethodForMainWorld()
#7 0x7fd75ece7487 blink::V8Node::appendChildMethodCallbackForMainWorld()
#8 0x7fd75fade2f2 v8::internal::FunctionCallbackArguments::Call()
#9 0x7fd75fbd99b3 v8::internal::(anonymous namespace)::HandleApiCallHelper<>()
#10 0x7fd75fbd7ba3 v8::internal::Builtin_Impl_HandleApiCall()
#11 0x7fd75fbd756d v8::internal::Builtin_HandleApiCall()
#12 0x29b70cc847e4 <unknown>

As the testcase uses createShadowRoot() which is Shadow DOM V0 API,
lowering the priority.

ClusterFuzz has detected this issue as fixed in range 512010:512063.

Detailed report: https://clusterfuzz.com/testcase?key=4556906655121408

Fuzzer: inferno_twister
Job Type: windows_asan_chrome
Platform Id: windows

Crash Type: Null-dereference READ
Crash Address: 0x00000008
Crash State:
  blink::Element::Shadow
  blink::ShadowWhereNodeCanBeDistributedForV0
  blink::Element::AttributeChanged
  
Sanitizer: address (ASAN)

Regressed: https://clusterfuzz.com/revisions?job=windows_asan_chrome&range=502136:502169
Fixed: https://clusterfuzz.com/revisions?job=windows_asan_chrome&range=512010:512063

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=4556906655121408

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 4556906655121408 is verified as fixed, so closing issue as verified.

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