it started failing in https://build.chromium.org/p/chromium.webkit/builders/WebKit%20Linux%20Trusty%20Leak/builds/9828.

Then failed up to #9839 except two times (#9836, #9837).

The error log is not helpful, I also don't see related CLs in 9828.

  "8/layout-test-results/http/tests/devtools/sources/debugger-ui/source-frame-count-actual.txt": "Tests that scripts panel does not create too many source frames.\n\n\nRunning: testSourceFramesCount\nReloading page...\nPage reloaded.\nToo many frames opened: 4\nVisible view: script5.js\n\n",
  "8/layout-test-results/http/tests/devtools/sources/debugger-ui/source-frame-count-diff.txt": "--- /b/s/w/ioYsQawr/layout-test-results/http/tests/devtools/sources/debugger-ui/source-frame-count-expected.txt\n+++ /b/s/w/ioYsQawr/layout-test-results/http/tests/devtools/sources/debugger-ui/source-frame-count-actual.txt\n@@ -4,6 +4,6 @@\n Running: testSourceFramesCount\n Reloading page...\n Page reloaded.\n-Less than 3 frames opened\n+Too many frames opened: 4\n Visible view: script5.js\n \n",
  "8/layout-test-results/http/tests/devtools/sources/debugger-ui/source-frame-count-expected.txt": "Tests that scripts panel does not create too many source frames.\n\n\nRunning: testSourceFramesCount\nReloading page...\nPage reloaded.\nLess than 3 frames opened\nVisible view: script5.js\n\n",
  "8/layout-test-results/http/tests/devtools/sources/debugger-ui/source-frame-count-pretty-diff.html": {
    "sha1": "dd1aac567348b939f401c6aec75dfa943334b513",
    "size": 784,
    "type": "binary"
  },

The test has been disabled on Linux already (see issue  crbug.com/763208 ).

oops, that test is actually mojo (virtual/mojo-loading/http/tests/devtools/sources/debugger-ui/source-frame-count.html).

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/c59f250cd11dff62c873229b477298a87eb08a1d

commit c59f250cd11dff62c873229b477298a87eb08a1d
Author: Vitalii Iarko <vitaliii@chromium.org>
Date: Wed Sep 20 10:14:54 2017

Disable h/t/devtools/sources/debugger-ui/source-frame-count.html (flaky)

No-Presubmit: true
No-Tree-Checks: true
No-Try: true
TBR: dgozman@chromium.org
Bug:  766952 
Change-Id: If40b0727b56a03268e7bbd5d88536924bb498cdc
Reviewed-on: https://chromium-review.googlesource.com/674687
Reviewed-by: vitaliii <vitaliii@chromium.org>
Commit-Queue: vitaliii <vitaliii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#503099}
[modify] https://crrev.com/c59f250cd11dff62c873229b477298a87eb08a1d/third_party/WebKit/LayoutTests/TestExpectations

chenwilliam@, you worked on this file 3 weeks ago, could you redirect please?
+cc dgozman who owns devtools.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/9f16ea7dd8aff4ec223fd690dc28c957151acd72

commit 9f16ea7dd8aff4ec223fd690dc28c957151acd72
Author: Elly Fong-Jones <ellyjones@chromium.org>
Date: Thu Sep 21 13:31:28 2017

sheriff: disable source-frame-count.html on Win10

This test is failing consistently with no apparent cause.

Bug:  766952 
Change-Id: Idd4ae1f2a3aca426c6a62ff5c52aaa52bdd7c545
TBR: chenwilliam@chromium.org
Reviewed-on: https://chromium-review.googlesource.com/676651
Reviewed-by: Vadym Doroshenko <dvadym@chromium.org>
Commit-Queue: Elly Fong-Jones <ellyjones@chromium.org>
Cr-Commit-Position: refs/heads/master@{#503432}
[modify] https://crrev.com/9f16ea7dd8aff4ec223fd690dc28c957151acd72/third_party/WebKit/LayoutTests/TestExpectations

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/fc9343892b854f945465fc1aa5b6d2d9cac9a5ac

commit fc9343892b854f945465fc1aa5b6d2d9cac9a5ac
Author: Jesse Doherty <jwd@chromium.org>
Date: Thu Sep 21 17:34:08 2017

sheriff: Disabling source-frame-count.html on Mac.

Started failing on https://uberchromegw.corp.google.com/i/chromium.mac/builders/Mac10.12%20Tests/builds/5541



Bug:  766952 
Change-Id: I564f7bef9365a392ceeff9be38ba6c70090bca3f
Reviewed-on: https://chromium-review.googlesource.com/677068
Reviewed-by: Elly Fong-Jones <ellyjones@chromium.org>
Commit-Queue: Jesse Doherty <jwd@chromium.org>
Cr-Commit-Position: refs/heads/master@{#503493}
[modify] https://crrev.com/fc9343892b854f945465fc1aa5b6d2d9cac9a5ac/third_party/WebKit/LayoutTests/TestExpectations

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/23787bf1fc8ed901459bccc471d97a7a31b441b1

commit 23787bf1fc8ed901459bccc471d97a7a31b441b1
Author: Jesse Doherty <jwd@chromium.org>
Date: Thu Sep 21 21:14:39 2017

sheriff: Disabling correct source-frame-count.html webkit_layout_test for Mac10.12.

Bug:  763208 ,  766952 
Change-Id: I1451eb7dd378ee8e9e65dd5d0f9b0a8e75265d45
TBR: japhet@chromium.org
Reviewed-on: https://chromium-review.googlesource.com/677628
Reviewed-by: Jesse Doherty <jwd@chromium.org>
Commit-Queue: Jesse Doherty <jwd@chromium.org>
Cr-Commit-Position: refs/heads/master@{#503565}
[modify] https://crrev.com/23787bf1fc8ed901459bccc471d97a7a31b441b1/third_party/WebKit/LayoutTests/TestExpectations

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/d6d2ff2cb4be3e573625e82f0e177ea3588ffe57

commit d6d2ff2cb4be3e573625e82f0e177ea3588ffe57
Author: Elly Fong-Jones <ellyjones@chromium.org>
Date: Fri Sep 22 21:44:24 2017

sheriff: disable source-frame-count.html on win10 + linux on mojo

Bug:  766952 
Change-Id: Ie4b23bcc31b4995615d2157a619e256609e2754d
TBR: japhet@chromium.org
No-Tree-Checks: True
Reviewed-on: https://chromium-review.googlesource.com/679295
Reviewed-by: Elly Fong-Jones <ellyjones@chromium.org>
Commit-Queue: Elly Fong-Jones <ellyjones@chromium.org>
Cr-Commit-Position: refs/heads/master@{#503865}
[modify] https://crrev.com/d6d2ff2cb4be3e573625e82f0e177ea3588ffe57/third_party/WebKit/LayoutTests/TestExpectations