Automatically applying components based on crash stacktrace and information from OWNERS files.

If this is incorrect, please apply the Test-Predator-Wrong-Components label.

Automatically assigning owner based on suspected regression changelist https://chromium.googlesource.com/chromium/src/+/dd4d74b8571682848ceb9c61af00e91a780a81a3 (Apply style changes when moreStyleSheets is updated).

If this is incorrect, please let us know why and apply the Test-Predator-Wrong-CLs label. If you aren't the correct owner for this issue, please unassign yourself as soon as possible so it can be re-triaged.

Not related to my change, as my change only affects document.moreStyleSheets, not document.styleSheets

It is actually caused by the moreStyleSheets patch.

https://chromium-review.googlesource.com/c/chromium/src/+/964326

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/a46b62e9900f5ac48951f8ad68d9e03eded4cc8d

commit a46b62e9900f5ac48951f8ad68d9e03eded4cc8d
Author: Rune Lillesveen <futhark@chromium.org>
Date: Fri Mar 16 09:07:53 2018

Create an empty StyleSheetList for moreStyleSheets.

We created a StyleSheetList connected to the TreeScope which would
create a second StyleSheetList for the scope-attached sheets which
messed up the active stylesheets causing crashes.

Bug:  819483 
Change-Id: Ib24bee538a27a64b5a8206e32334d4324629d5af
Reviewed-on: https://chromium-review.googlesource.com/964326
Commit-Queue: Rune Lillesveen <futhark@chromium.org>
Reviewed-by: Rakina Zata Amni <rakina@chromium.org>
Reviewed-by: Takayoshi Kochi <kochi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#543654}
[modify] https://crrev.com/a46b62e9900f5ac48951f8ad68d9e03eded4cc8d/third_party/WebKit/LayoutTests/fast/css/CSSStyleSheet-constructable.html
[modify] https://crrev.com/a46b62e9900f5ac48951f8ad68d9e03eded4cc8d/third_party/WebKit/Source/core/css/StyleSheetList.cpp
[modify] https://crrev.com/a46b62e9900f5ac48951f8ad68d9e03eded4cc8d/third_party/WebKit/Source/core/css/StyleSheetList.h
[modify] https://crrev.com/a46b62e9900f5ac48951f8ad68d9e03eded4cc8d/third_party/WebKit/Source/core/dom/TreeScope.cpp

ClusterFuzz has detected this issue as fixed in range 543652:543656.

Detailed report: https://clusterfuzz.com/testcase?key=6385692901638144

Fuzzer: inferno_twister
Job Type: mac_asan_content_shell
Platform Id: mac

Crash Type: Null-dereference READ
Crash Address: 0x0000000001c0
Crash State:
  blink::ScopedStyleResolver::CollectMatchingAuthorRules
  blink::MatchElementScopeRules
  blink::StyleResolver::MatchScopedRules
  
Sanitizer: address (ASAN)

Regressed: https://clusterfuzz.com/revisions?job=mac_asan_content_shell&range=539112:539114
Fixed: https://clusterfuzz.com/revisions?job=mac_asan_content_shell&range=543652:543656

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=6385692901638144

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 6385692901638144 is verified as fixed, so closing issue as verified.

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