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/+/b13215c5663aede68435bdb2dce670ad9d7dff34 (Add effect parent alias with alias unwrapping.).

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.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b3cb7ce6ac95537e55d8c9da3105b411933bd7e0

commit b3cb7ce6ac95537e55d8c9da3105b411933bd7e0
Author: Vladimir Levin <vmpstr@chromium.org>
Date: Fri Sep 14 20:07:03 2018

Fix nullptr deref when Unaliasing an effect node.

My previous patch missed one spot where we can unalias a node which
is actually null. This patch fixes up that spot.

R=pdr@chromium.org, chrishtr@chromium.org

Bug:  884081 ,  884083 ,  884084 , 884186
Cq-Include-Trybots: luci.chromium.try:linux_layout_tests_slimming_paint_v2;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: Ic12a21c429c4984cb18f92f6beac8c18c0f51f87
Reviewed-on: https://chromium-review.googlesource.com/1227147
Reviewed-by: Philip Rogers <pdr@chromium.org>
Reviewed-by: vmpstr <vmpstr@chromium.org>
Commit-Queue: vmpstr <vmpstr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#591444}
[modify] https://crrev.com/b3cb7ce6ac95537e55d8c9da3105b411933bd7e0/third_party/blink/renderer/platform/graphics/compositing/chunk_to_layer_mapper.cc
[modify] https://crrev.com/b3cb7ce6ac95537e55d8c9da3105b411933bd7e0/third_party/blink/renderer/platform/graphics/compositing/chunk_to_layer_mapper_test.cc

ClusterFuzz has detected this issue as fixed in range 591443:591444.

Detailed report: https://clusterfuzz.com/testcase?key=4822279459176448

Fuzzer: ifratric-browserfuzzer-v3
Job Type: linux_ubsan_chrome
Platform Id: linux

Crash Type: Null-dereference READ
Crash Address: 0x000000000008
Crash State:
  blink::PaintPropertyNode<blink::EffectPaintPropertyNode>::Unalias
  blink::ChunkToLayerMapper::SwitchToChunk
  blink::RasterInvalidator::Generate
  
Sanitizer: undefined (UBSAN)

Regressed: https://clusterfuzz.com/revisions?job=linux_ubsan_chrome&range=591121:591123
Fixed: https://clusterfuzz.com/revisions?job=linux_ubsan_chrome&range=591443:591444

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=4822279459176448

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 4822279459176448 is verified as fixed, so closing issue as verified.

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