This seems to be blocking V8 rolls - fortunately, it looks like this hasn't made it into the source tree.

Shows up here:

https://ci.chromium.org/p/chromium/builders/luci.chromium.try/linux_optional_gpu_tests_rel?limit=200

Only a few failures:

https://ci.chromium.org/p/chromium/builders/luci.chromium.try/linux_optional_gpu_tests_rel/5252
https://ci.chromium.org/p/chromium/builders/luci.chromium.try/linux_optional_gpu_tests_rel/5247
https://ci.chromium.org/p/chromium/builders/luci.chromium.try/linux_optional_gpu_tests_rel/5241
https://ci.chromium.org/p/chromium/builders/luci.chromium.try/linux_optional_gpu_tests_rel/5230
https://ci.chromium.org/p/chromium/builders/luci.chromium.try/linux_optional_gpu_tests_rel/5226
https://ci.chromium.org/p/chromium/builders/luci.chromium.try/linux_optional_gpu_tests_rel/5223
https://ci.chromium.org/p/chromium/builders/luci.chromium.try/linux_optional_gpu_tests_rel/5220

One concrete example:

https://ci.chromium.org/p/chromium/builders/luci.chromium.try/linux_optional_gpu_tests_rel/5113
https://chromium-swarm.appspot.com/task?id=3e5b221db8028110&refresh=10&show_raw=1

Stack trace:

[107/134] gpu_tests.webgl_conformance_integration_test.WebGLConformanceIntegrationTest.WebglConformance_deqp_functional_gles3_shaderoperator_common_functions failed unexpectedly 120.1401s:
  No path to crashpad_database_util found
  No minidump found via crashpad_database_util
  Found minidump via globbing in minidump dir
  Minidump found: /b/swarm_slave/w/itboQdMl/tmp_OuTCu/chromium-renderer-minidump-954b2c22015937c3.dmp
  Uploading /b/swarm_slave/w/itboQdMl/tmp_OuTCu/chromium-renderer-minidump-954b2c22015937c3.dmp to gs://chrome-telemetry-output/minidump-2018-06-27_10-38-29-73108.dmp
  Dumping breakpad symbols.
  No path to crashpad_database_util found
  No minidump found via crashpad_database_util
  Found minidump via globbing in minidump dir
  Can't get standard output with --show-stdout
  
Traceback (most recent call last):
[...]
  DevtoolsTargetCrashException: Devtools target crashed
  ********************************************************************************
  (/b/swarm_slave/w/ir/third_party/catapult/telemetry/telemetry/internal/backends/chrome_inspector/inspector_backend.py:513 _AddDebuggingInformation) Received a socket error in the browser connection and the tab no longer exists. The tab probably crashed.
  ********************************************************************************
  (/b/swarm_slave/w/ir/third_party/catapult/telemetry/telemetry/internal/backends/chrome_inspector/inspector_backend.py:514 _AddDebuggingInformation) Debugger url: ws://127.0.0.1:39030/devtools/page/E7FD07CB89A63A15FA59DB7CB627696E
  Found Minidump: True
  Stack Trace:
  ********************************************************************************
  	Operating system: Linux
  	                  0.0.0 Linux 3.13.0-91-generic #138-Ubuntu SMP Fri Jun 24 17:00:34 UTC 2016 x86_64
  	CPU: amd64
  	     family 6 model 94 stepping 3
  	     1 CPU
  	
  	GPU: UNKNOWN
  	
  	Crash reason:  SIGSEGV
  	Crash address: 0x0
  	Process uptime: not available
  	
  	Thread 0 (crashed)
  	 0  libc-2.19.so + 0x3a177
  	    rax = 0x0000000000000006   rdx = 0x0000000000000006
  	    rcx = 0xffffffffffffffff   rbx = 0x0000000000000034
  	    rsi = 0x0000000000000001   rdi = 0x0000000000000001
  	    rbp = 0x00007ffdc6ebc2b0   rsp = 0x00007ffdc6ebc180
  	     r8 = 0x0000000000000000    r9 = 0x00007ffdc6ebc0d0
  	    r10 = 0x0000000000000008   r11 = 0x0000000000000202
  	    r12 = 0x00007ffdc6ebc780   r13 = 0x00007ffdc6ebc770
  	    r14 = 0x00007ffdc6ebc778   r15 = 0x000010c7b723546f
  	    rip = 0x00007f77ecc46177
  	    Found by: given as instruction pointer in context
  	 1  chrome!~LogMessage [callback.h : 129 + 0x7]
  	    rbp = 0x00007ffdc6ebc750   rsp = 0x00007ffdc6ebc2c0
  	    rip = 0x00007f77f87f620f
  	    Found by: previous frame's frame pointer
  	 2  chrome!GetBlackHoleMad [process_memory_dump.cc : 484 + 0x8]
  	    rbx = 0x00007ffdc6ebc770   rbp = 0x00007ffdc6ebc8c0
  	    rsp = 0x00007ffdc6ebc760   r12 = 0x0000000000000000
  	    r13 = 0x0000000000000000   r14 = 0x000010c7b7aefae0
  	    r15 = 0x000010c7b7aefae0   rip = 0x00007f77f886aa6b
  	    Found by: call frame info
  	 3  chrome!AddAllocatorDumpInternal [process_memory_dump.cc : 259 + 0x8]
  	    rbx = 0x00007ffdc6ebca60   rbp = 0x00007ffdc6ebca40
  	    rsp = 0x00007ffdc6ebc8d0   r12 = 0x0000000000000000
  	    r13 = 0x0000000000000000   r14 = 0x000010c7b7aefae0
  	    r15 = 0x000010c7b7aefae0   rip = 0x00007f77f886a858
  	    Found by: call frame info
  	 4  chrome!CreateAllocatorDump [process_memory_dump.cc : 242 + 0x8]
  	    rbx = 0x000010c7b73ace60   rbp = 0x00007ffdc6ebca80
  	    rsp = 0x00007ffdc6ebca50   r12 = 0x0000000000000000
  	    r13 = 0x0000000000000000   r14 = 0x00007ffdc6ebcbd0
  	    r15 = 0x000010c7b7aefae0   rip = 0x00007f77f886a71c
  	    Found by: call frame info
  	 5  chrome!DumpHeapStatistics [v8_isolate_memory_dump_provider.cc : 151 + 0x13]
  	    rbx = 0x0000000000000006   rbp = 0x00007ffdc6ebcd60
  	    rsp = 0x00007ffdc6ebca90   r12 = 0x0000000000000000
  	    r13 = 0x0000000000000000   r14 = 0x00007ffdc6ebcbb0
  	    r15 = 0x00007f77f370b398   rip = 0x00007f77fb7f5c41
  	    Found by: call frame info
  	 6  chrome!OnMemoryDump [v8_isolate_memory_dump_provider.cc : 44 + 0xe]
  	    rbx = 0x000010c7b701e6c0   rbp = 0x00007ffdc6ebcda0
  	    rsp = 0x00007ffdc6ebcd70   r12 = 0x000010c7b6f49db8
  	    r13 = 0x000010c7b6fe7d01   r14 = 0x000010c7b7aefae0
  	    r15 = 0x000010c7b7aefb20   rip = 0x00007f77fb7f5a78
  	    Found by: call frame info
  	 7  chrome!InvokeOnMemoryDump [memory_dump_manager.cc : 458 + 0x6]
  	    rbx = 0x00007ffdc6ebcdf0   rbp = 0x00007ffdc6ebcf60
  	    rsp = 0x00007ffdc6ebcdb0   r12 = 0x000010c7b6f49db8
  	    r13 = 0x000010c7b6fe7d01   r14 = 0x000010c7b74e1301
  	    r15 = 0x000010c7b6fe7d40   rip = 0x00007f77f88670d9
  	    Found by: call frame info
  	 8  chrome!ContinueAsyncProcessDump [memory_dump_manager.cc : 372 + 0xf]
  	    rbx = 0x000010c7b747bf38   rbp = 0x00007ffdc6ebd120
  	    rsp = 0x00007ffdc6ebcf70   r12 = 0x000010c7b74e13c0
  	    r13 = 0x000010c7b6fe7d40   r14 = 0x000010c7b74e13e0
  	    r15 = 0x000010c7b6fd97a0   rip = 0x00007f77f8866c65
  	    Found by: call frame info
  	 9  chrome!CreateProcessDump [memory_dump_manager.cc : 319 + 0xf]
  	    rbx = 0x000010c7b6f49db0   rbp = 0x00007ffdc6ebd2f0
  	    rsp = 0x00007ffdc6ebd130   r12 = 0x0000000000000002
  	    r13 = 0x000010c7b6f49d88   r14 = 0x000010c7b74e13c0
  	    r15 = 0x000010c7b6f49d80   rip = 0x00007f77f886698d
  	    Found by: call frame info
  	10  chrome!RequestChromeMemoryDump [client_process_impl.cc : 84 + 0xe]
  	    rbx = 0x000010c7b740e500   rbp = 0x00007ffdc6ebd460
  	    rsp = 0x00007ffdc6ebd300   r12 = 0x00007ffdc6ebd308
  	    r13 = 0x000010c7b6f45180   r14 = 0x00007ffdc6ebd4b0
  	    r15 = 0x000010c7b6f49d80   rip = 0x00007f77fa11cfda
  	    Found by: call frame info
  	11  chrome!AcceptWithResponder [memory_instrumentation.mojom.cc : 905 + 0x1a]
  	    rbx = 0x00007ffdc6ebd4a0   rbp = 0x00007ffdc6ebd640
  	    rsp = 0x00007ffdc6ebd470   r12 = 0x0000000000000001
  	    r13 = 0x000010c7b7a1d660   r14 = 0x000010c7b6f45180
  	    r15 = 0x00007ffdc6ebd4e8   rip = 0x00007f77fa1354bb
  	    Found by: call frame info
  	12  chrome!AcceptWithResponder [memory_instrumentation.mojom.h : 474 + 0x5]
  	    rbx = 0x000010c7b7a1d660   rbp = 0x00007ffdc6ebd660
  	    rsp = 0x00007ffdc6ebd650   r12 = 0x00007ffdc6ebd698
  	    r13 = 0x000010c7b6fcb160   r14 = 0x00007ffdc6ebdac8
  	    r15 = 0x000010c7b6f686e0   rip = 0x00007f77fa11da16
  	    Found by: call frame info
  	13  chrome!HandleValidatedMessage [interface_endpoint_client.cc : 394 + 0x10]
...

Please investigate. It's a relief this didn't make it through the commit queue.