Looks like a conflict between libclearkey.so and test libraries:

[ RUN      ] CDM_9/CdmAdapterTestWithClearKeyCdm.CreateSessionWithBadData/0
=================================================================
==22532==ERROR: AddressSanitizer: odr-violation (0x000009c5be80):
  [1] size=40 'zwp_linux_dmabuf_v1_interface' ../../third_party/wayland-protocols/protocol/linux-dmabuf-protocol.c:59:37
  [2] size=40 'zwp_linux_dmabuf_v1_interface' ../../third_party/wayland-protocols/protocol/linux-dmabuf-protocol.c:59:37
These globals were registered at these points:
  [1]:
    #0 0x5b211e in __asan_register_globals /b/swarming/w/ir/kitchen-workdir/src/third_party/llvm/compiler-rt/lib/asan/asan_globals.cc:359:3
    #1 0x7f122bbbf87b in asan.module_ctor (/b/s/w/ir/out/Release/libclearkeycdm.so+0x2c8b87b)
  [2]:
    #0 0x5b211e in __asan_register_globals /b/swarming/w/ir/kitchen-workdir/src/third_party/llvm/compiler-rt/lib/asan/asan_globals.cc:359:3
    #1 0x37b667b in asan.module_ctor (/b/s/w/ir/out/Release/media_unittests+0x37b667b)
==22532==HINT: if you don't care about these errors you may set ASAN_OPTIONS=detect_odr_violation=0
SUMMARY: AddressSanitizer: odr-violation: global 'zwp_linux_dmabuf_v1_interface' at ../../third_party/wayland-protocols/protocol/linux-dmabuf-protocol.c:59:37
==22532==ABORTING

https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Linux%20Chromium%20OS%20ASan%20LSan%20Tests%20%281%29/29063 is the first build that ran into this.

+spang, piman for https://chromium-review.googlesource.com/c/chromium/src/+/1234374

Do you think enabling vulcan caused linux_dmabuf_protocol to be pulled in from both libclearkeycdm and browser?

I thought the chromite autoroll might have been the culprit
https://chromium-review.googlesource.com/c/chromium/src/+/1233996

Since one of the rolled CLs was: 
2018-09-19 manojgupta@google.com chrome_util: Make widevine cdm optional for ARM64.

@#4: that CL should have no impact on Chrome OS (only touches Fuchsia)

My CL in #5 does not affect anything related to the fails. It only ensures that missing libwidevinecdm.so does not trigger an error on an official arm64 build so does not even apply to chromium.

Re piman / spang: What about this CL in the blamelist? https://chromium-review.googlesource.com/c/chromium/src/+/1229233

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/424dfd0e97288afc91744841bfede2496cc66db5

commit 424dfd0e97288afc91744841bfede2496cc66db5
Author: Michael Spang <spang@chromium.org>
Date: Wed Sep 19 22:30:31 2018

Revert "ozone: Enable vulkan by default"

This reverts commit f3c9ed0efe2ade7757607bcf356712883c315450.

Reason for revert: breaks Linux Chromium OS ASan LSan Tests

Bug:  887048 

Original change's description:
> ozone: Enable vulkan by default
> 
> Vulkan is enabled by default on Linux desktop (X11) builds. Enable it on
> ozone as well to make sure we have build coverage.
> 
> Bug: 861853
> Test: compile
> Change-Id: I7c15e365b2a4cfc7160847457ce9bf46a3f12f1e
> Reviewed-on: https://chromium-review.googlesource.com/1229233
> Commit-Queue: Michael Spang <spang@chromium.org>
> Reviewed-by: Antoine Labour <piman@chromium.org>
> Reviewed-by: Chris Blume <cblume@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#592451}

TBR=spang@chromium.org,piman@chromium.org,cblume@chromium.org

Change-Id: I6a95fdfdb742e4a876382c72b212bacd2b601c23
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 861853
Reviewed-on: https://chromium-review.googlesource.com/1235194
Commit-Queue: Michael Spang <spang@chromium.org>
Reviewed-by: Michael Spang <spang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#592579}
[modify] https://crrev.com/424dfd0e97288afc91744841bfede2496cc66db5/gpu/vulkan/features.gni
[modify] https://crrev.com/424dfd0e97288afc91744841bfede2496cc66db5/gpu/vulkan/init/vulkan_factory.cc

I'm not sure exactly why vulkan is trigger this but clear_key_cdm seems to have a sizable overlap with chrome in that it pulls //media into a standalone library.

Filed  bug 887110  to follow up.