Got the same crash again today. I will disable the test to avoid causing more problems while this is being triaged.

10:18:08.851 30643 worker/1 fast/imagecapture/MediaStreamTrack-getConstraints.html crashed, (stderr lines):
10:18:08.851 30643   [30649:30715:0707/101808.479968:6700521274:ERROR:devtools_http_handler.cc(786)] 
10:18:08.851 30643   DevTools listening on 127.0.0.1:55550
10:18:08.851 30643   
10:18:08.851 30643   Xlib:  extension "RANDR" missing on display ":100".
10:18:08.851 30643   Failed to tell parent about crash.
10:18:08.851 30643   Received signal 11 SEGV_ACCERR 6140002a0000
10:18:08.851 30643   #0 0x000000481371 (/b/s/w/ir/out/Release/content_shell+0x481370)
10:18:08.851 30643   #1 0x0000048922dc (/b/s/w/ir/out/Release/content_shell+0x48922db)
10:18:08.851 30643   #2 0x0000048912dc (/b/s/w/ir/out/Release/content_shell+0x48912db)
10:18:08.851 30643   #3 0x7f59c172e330 (/lib/x86_64-linux-gnu/libpthread-2.19.so+0x1032f)
10:18:08.851 30643   #4 0x000007144ab6 (/b/s/w/ir/out/Release/content_shell+0x7144ab5)
10:18:08.852 30643   #5 0x000007115b65 (/b/s/w/ir/out/Release/content_shell+0x7115b64)
10:18:08.852 30643   #6 0x00000710b44b (/b/s/w/ir/out/Release/content_shell+0x710b44a)
10:18:08.852 30643   #7 0x00000b599532 (/b/s/w/ir/out/Release/content_shell+0xb599531)
10:18:08.852 30643   #8 0x0000097325e3 (/b/s/w/ir/out/Release/content_shell+0x97325e2)
10:18:08.852 30643   #9 0x000009732b0e (/b/s/w/ir/out/Release/content_shell+0x9732b0d)
10:18:08.852 30643   #10 0x00000995d02f (/b/s/w/ir/out/Release/content_shell+0x995d02e)
10:18:08.852 30643   #11 0x00000ab58456 (/b/s/w/ir/out/Release/content_shell+0xab58455)
10:18:08.852 30643   #12 0x000008ac243d (/b/s/w/ir/out/Release/content_shell+0x8ac243c)
10:18:08.852 30643   #13 0x000008abc175 (/b/s/w/ir/out/Release/content_shell+0x8abc174)
10:18:08.852 30643   #14 0x000004a60c58 (/b/s/w/ir/out/Release/content_shell+0x4a60c57)
10:18:08.852 30643   #15 0x0000048ec4b4 (/b/s/w/ir/out/Release/content_shell+0x48ec4b3)
10:18:08.852 30643   #16 0x0000048ed401 (/b/s/w/ir/out/Release/content_shell+0x48ed400)
10:18:08.852 30643   #17 0x0000048ee16e (/b/s/w/ir/out/Release/content_shell+0x48ee16d)
10:18:08.852 30643   #18 0x0000048f51ef (/b/s/w/ir/out/Release/content_shell+0x48f51ee)
10:18:08.852 30643   #19 0x000004952878 (/b/s/w/ir/out/Release/content_shell+0x4952877)
10:18:08.852 30643   #20 0x00000b45ece6 (/b/s/w/ir/out/Release/content_shell+0xb45ece5)
10:18:08.852 30643   #21 0x000003003c00 (/b/s/w/ir/out/Release/content_shell+0x3003bff)
10:18:08.852 30643   #22 0x000003006b08 (/b/s/w/ir/out/Release/content_shell+0x3006b07)
10:18:08.852 30643   #23 0x000007d9cd99 (/b/s/w/ir/out/Release/content_shell+0x7d9cd98)
10:18:08.852 30643   #24 0x000001315f17 (/b/s/w/ir/out/Release/content_shell+0x1315f16)
10:18:08.852 30643   #25 0x00000050127a (/b/s/w/ir/out/Release/content_shell+0x501279)
10:18:08.852 30643   #26 0x7f59bfa33f45 (/lib/x86_64-linux-gnu/libc-2.19.so+0x21f44)
10:18:08.852 30643   #27 0x0000004363fc (/b/s/w/ir/out/Release/content_shell+0x4363fb)
10:18:08.852 30643     r8: 00007ffe20b2b060  r9: fffff014496fb504 r10: 00000febb6904ad4 r11: 0000000000000004
10:18:08.852 30643    r12: 0000000000000000 r13: 000000000000000a r14: 000061400029ffa8 r15: 00007f59b4865600
10:18:08.852 30643     di: 000061400029ffa8  si: 000061d000083b10  bp: 00007ffe20b2b0b0  bx: 00007ffe20b2b0c0
10:18:08.852 30643     dx: 000000000000000a  ax: 0000000000000003  cx: 00000fffc4165608  sp: 00007ffe20b2b040
10:18:08.852 30643     ip: 0000000007144ab6 efl: 0000000000010297 cgf: 0000000000000033 erf: 0000000000000004
10:18:08.852 30643    trp: 000000000000000e msk: 0000000000000000 cr2: 00006140002a0000
10:18:08.852 30643   [end of stack trace]
10:18:08.852 30643   Calling _exit(1). Core file will not be generated.
10:18:08.857 17511 [1/2] fast/imagecapture/MediaStreamTrack-getConstraints.html failed unexpectedly (renderer crashed)

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b2fe75e1b087756ed6ff7063eec18f32997938b6

commit b2fe75e1b087756ed6ff7063eec18f32997938b6
Author: Bret Sepulveda <bsep@chromium.org>
Date: Fri Jul 07 19:56:46 2017

Mark fast/imagecapture/MediaStreamTrack-getConstraints.html crash-flaky.

Bug:  739409 
TBR: mcasas@chromium.org
Change-Id: I46c9073ca62badef7b22c78f8060c6570d008438
Reviewed-on: https://chromium-review.googlesource.com/563760
Reviewed-by: Bret Sepulveda <bsep@chromium.org>
Commit-Queue: Bret Sepulveda <bsep@chromium.org>
Cr-Commit-Position: refs/heads/master@{#485012}
[modify] https://crrev.com/b2fe75e1b087756ed6ff7063eec18f32997938b6/third_party/WebKit/LayoutTests/TestExpectations

I believe that  https://crbug.com/759457  (and its crrev.com/c/701358)
fixed this issue. Will revert #3 and see if it stays crash free.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/d91c2da119bfb5c34b28e4f794d06c653bf2730f

commit d91c2da119bfb5c34b28e4f794d06c653bf2730f
Author: Miguel Casas-Sanchez <mcasas@chromium.org>
Date: Mon Oct 23 16:02:54 2017

Revert "Mark fast/imagecapture/MediaStreamTrack-getConstraints.html crash-flaky."

This reverts commit b2fe75e1b087756ed6ff7063eec18f32997938b6, removing
the crash-flaky annotation of a test, because that problem should have
been addressed, see [1].

Original CL description:
https://chromium-review.googlesource.com/c/chromium/src/+/563760


[1] https://bugs.chromium.org/p/chromium/issues/detail?id=739409#c4


Bug:  739409 
Change-Id: Ic8a4a5a396e9fdce1d7c9ee423a7eecbdb545846
Reviewed-on: https://chromium-review.googlesource.com/732041
Reviewed-by: Reilly Grant <reillyg@chromium.org>
Commit-Queue: Miguel Casas <mcasas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#510807}
[modify] https://crrev.com/d91c2da119bfb5c34b28e4f794d06c653bf2730f/third_party/WebKit/LayoutTests/TestExpectations

Monitoring https://test-results.appspot.com/dashboards/flakiness_dashboard.html#testType=webkit_tests&tests=imagecapture%2F

The NextAction date has arrived: 2017-10-31