Version: tip
OS: Linux

What steps will reproduce the problem?
(1) Build sandbox_linux_unittests in the official mode:
$ gn gen out/gn-off '--args=is_chrome_branded=true is_official_build=true is_debug=false' --check
$ ninja -C out/gn-off sandbox_linux_unittests
(2) Run sandbox_linux_unittests:
$ ./out/gn-off/sandbox_linux_unittests
...
4 tests failed:
    BrokerFilePermission.CreateBad (../../sandbox/linux/syscall_broker/broker_file_permission_unittest.cc:52)
    BrokerFilePermission.CreateBadEmpty (../../sandbox/linux/syscall_broker/broker_file_permission_unittest.cc:76)
    BrokerFilePermission.CreateBadNotAbs (../../sandbox/linux/syscall_broker/broker_file_permission_unittest.cc:68)
    BrokerFilePermission.CreateBadRecursive (../../sandbox/linux/syscall_broker/broker_file_permission_unittest.cc:60)

Looking closer at one of the failures:

$ ./out/gn-off/sandbox_linux_unittests --gtest_filter=BrokerFilePermission.CreateBad
IMPORTANT DEBUGGING NOTE: batches of tests are run inside their
own process. For debugging a test inside a debugger, use the
--gtest_filter=<your_test_name> flag along with
--single-process-tests.
Using sharding settings from environment. This is shard 0/1
Using 1 parallel jobs.
Note: Google Test filter = BrokerFilePermission.CreateBad
[==========] Running 1 test from 1 test case.
[----------] Global test environment set-up.
[----------] 1 test from BrokerFilePermission
[ RUN      ] BrokerFilePermission.CreateBad
../../sandbox/linux/tests/unit_tests.cc:300: Failure
Value of: subprocess_exited_without_matching_message
  Actual: true
Expected: false
Actual test failure: Received signal 4 ILL_ILLOPN 0000004713e5
#0 0x0000004ea6d7 (/usr/local/google/home/krasin/chr22/src/out/gn-off/sandbox_linux_unittests+0x4ea6d6)
  r8: 000002e0eac32048  r9: 0000000000000000 r10: 0000000000000008 r11: 0000000000000246
 r12: 0000000000000000 r13: 00007ffc6b59f900 r14: 0000000000000000 r15: 0000000000000001
  di: 000002e0eac32000  si: 00007ffc6b59f76f  bp: 0000000000000000  bx: 00007ffc6b59f820
  dx: 000002e0eac32030  ax: 000000000000002f  cx: 0000000000000009  sp: 00007ffc6b59f7c0
  ip: 00000000004713e5 efl: 0000000000010246 cgf: 0000000000000033 erf: 0000000000000000
 trp: 0000000000000006 msk: 0000000000000000 cr2: 0000000000000000
[end of stack trace]

[  FAILED  ] BrokerFilePermission.CreateBad (2 ms)
[----------] 1 test from BrokerFilePermission (2 ms total)

[----------] Global test environment tear-down
[==========] 1 test from 1 test case ran. (2 ms total)
[  PASSED  ] 0 tests.
[  FAILED  ] 1 test, listed below:
[  FAILED  ] BrokerFilePermission.CreateBad

 1 FAILED TEST
[1/1] BrokerFilePermission.CreateBad (2 ms)
1 test failed:
    BrokerFilePermission.CreateBad (../../sandbox/linux/syscall_broker/broker_file_permission_unittest.cc:52)


This failure only happens in the official mode. Please, take a look.

Note: the failure seems somewhat similar to  https://crbug.com/612503 , but it seems to be a distinct issue.