yoshiki@ seems an owner of the test.  Could you take a look?
The test results are as follows.


ToastManagerTest.PositionWithVisibleLeftShelf (run #1):
[ RUN      ] ToastManagerTest.PositionWithVisibleLeftShelf
e:\c\win\srcsh\system	oast	oast_manager_unittest.cc(238): error: Value of: round(precise_toast_bounds.CenterPoint().x())
  Actual: 423
Expected: round(shelf_bounds.right() + (root_bounds.width() - shelf_bounds.width()) / 2.0)
Which is: 424
[  FAILED  ] ToastManagerTest.PositionWithVisibleLeftShelf (29 ms)

ToastManagerTest.PositionWithVisibleLeftShelf (run #2):
[ RUN      ] ToastManagerTest.PositionWithVisibleLeftShelf
e:\c\win\srcsh\system	oast	oast_manager_unittest.cc(238): error: Value of: round(precise_toast_bounds.CenterPoint().x())
  Actual: 423
Expected: round(shelf_bounds.right() + (root_bounds.width() - shelf_bounds.width()) / 2.0)
Which is: 424
[  FAILED  ] ToastManagerTest.PositionWithVisibleLeftShelf (31 ms)

ToastManagerTest.PositionWithVisibleLeftShelf (run #3):
[ RUN      ] ToastManagerTest.PositionWithVisibleLeftShelf
e:\c\win\srcsh\system	oast	oast_manager_unittest.cc(238): error: Value of: round(precise_toast_bounds.CenterPoint().x())
  Actual: 423
Expected: round(shelf_bounds.right() + (root_bounds.width() - shelf_bounds.width()) / 2.0)
Which is: 424
[  FAILED  ] ToastManagerTest.PositionWithVisibleLeftShelf (16 ms)

ToastManagerTest.PositionWithVisibleLeftShelf (run #4):
[ RUN      ] ToastManagerTest.PositionWithVisibleLeftShelf
e:\c\win\srcsh\system	oast	oast_manager_unittest.cc(238): error: Value of: round(precise_toast_bounds.CenterPoint().x())
  Actual: 423
Expected: round(shelf_bounds.right() + (root_bounds.width() - shelf_bounds.width()) / 2.0)
Which is: 424
[  FAILED  ] ToastManagerTest.PositionWithVisibleLeftShelf (32 ms)

Detected 5 new flakes for test/step "ToastManagerTest.PositionWithVisibleLeftShelf". To see the actual flakes, please visit https://chromium-try-flakes.appspot.com/all_flake_occurrences?key=ahVzfmNocm9taXVtLXRyeS1mbGFrZXNyOAsSBUZsYWtlIi1Ub2FzdE1hbmFnZXJUZXN0LlBvc2l0aW9uV2l0aFZpc2libGVMZWZ0U2hlbGYM. This message was posted automatically by the chromium-try-flakes app. Since flakiness is ongoing, the issue was moved back into Sheriff Bug Queue (unless already there).

Ping yoshiki@, can you please take a look at this test flake?

Detected 12 new flakes for test/step "ToastManagerTest.PositionWithVisibleLeftShelf". To see the actual flakes, please visit https://chromium-try-flakes.appspot.com/all_flake_occurrences?key=ahVzfmNocm9taXVtLXRyeS1mbGFrZXNyOAsSBUZsYWtlIi1Ub2FzdE1hbmFnZXJUZXN0LlBvc2l0aW9uV2l0aFZpc2libGVMZWZ0U2hlbGYM. This message was posted automatically by the chromium-try-flakes app.

Let me look

Detected 9 new flakes for test/step "ToastManagerTest.PositionWithVisibleLeftShelf". To see the actual flakes, please visit https://chromium-try-flakes.appspot.com/all_flake_occurrences?key=ahVzfmNocm9taXVtLXRyeS1mbGFrZXNyOAsSBUZsYWtlIi1Ub2FzdE1hbmFnZXJUZXN0LlBvc2l0aW9uV2l0aFZpc2libGVMZWZ0U2hlbGYM. This message was posted automatically by the chromium-try-flakes app.

Detected 3 new flakes for test/step "ToastManagerTest.PositionWithVisibleLeftShelf". To see the actual flakes, please visit https://chromium-try-flakes.appspot.com/all_flake_occurrences?key=ahVzfmNocm9taXVtLXRyeS1mbGFrZXNyOAsSBUZsYWtlIi1Ub2FzdE1hbmFnZXJUZXN0LlBvc2l0aW9uV2l0aFZpc2libGVMZWZ0U2hlbGYM. This message was posted automatically by the chromium-try-flakes app.

Detected 5 new flakes for test/step "ToastManagerTest.PositionWithVisibleLeftShelf". To see the actual flakes, please visit https://chromium-try-flakes.appspot.com/all_flake_occurrences?key=ahVzfmNocm9taXVtLXRyeS1mbGFrZXNyOAsSBUZsYWtlIi1Ub2FzdE1hbmFnZXJUZXN0LlBvc2l0aW9uV2l0aFZpc2libGVMZWZ0U2hlbGYM. This message was posted automatically by the chromium-try-flakes app.

Detected 5 new flakes for test/step "ToastManagerTest.PositionWithVisibleLeftShelf". To see the actual flakes, please visit https://chromium-try-flakes.appspot.com/all_flake_occurrences?key=ahVzfmNocm9taXVtLXRyeS1mbGFrZXNyOAsSBUZsYWtlIi1Ub2FzdE1hbmFnZXJUZXN0LlBvc2l0aW9uV2l0aFZpc2libGVMZWZ0U2hlbGYM. This message was posted automatically by the chromium-try-flakes app. Since flakiness is ongoing, the issue was moved back into Sheriff Bug Queue (unless already there).

Seems like a flaky off-by-one error.

@yoshiki please disable test by policy if you can't get it to pass promptly:

" Flaky tests should be disabled within 30 minutes unless culprit CL is found and reverted. Please see more details here: https://sites.google.com/a/chromium.org/dev/developers/tree-sheriffs/sheriffing-bug-queues#triaging-auto-filed-flakiness-bugs "

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/d7cbf7ccc5f21177c925657fd50c688ca437526a

commit d7cbf7ccc5f21177c925657fd50c688ca437526a
Author: gab <gab@chromium.org>
Date: Thu Oct 06 19:42:20 2016

Log extra information on weird ToastManagerTest.PositionWithVisibleLeftShelf flake.

BUG= 650925 
TBR=sadrul

Review-Url: https://codereview.chromium.org/2394483006
Cr-Commit-Position: refs/heads/master@{#423635}

[modify] https://crrev.com/d7cbf7ccc5f21177c925657fd50c688ca437526a/ash/system/toast/toast_manager_unittest.cc

Detected 9 new flakes for test/step "ToastManagerTest.PositionWithVisibleLeftShelf". To see the actual flakes, please visit https://chromium-try-flakes.appspot.com/all_flake_occurrences?key=ahVzfmNocm9taXVtLXRyeS1mbGFrZXNyOAsSBUZsYWtlIi1Ub2FzdE1hbmFnZXJUZXN0LlBvc2l0aW9uV2l0aFZpc2libGVMZWZ0U2hlbGYM. This message was posted automatically by the chromium-try-flakes app. Since flakiness is ongoing, the issue was moved back into Sheriff Bug Queue (unless already there).

From the logs it looks like the result arrives at 423.5 -- I guess that's
somehow nondeterministically rounded up/down depending on the precision of float
arithmetic?! Maybe even depends on a given bot's CPU architecture? e.g. whether
it's holding 423.50000000000000001 or 423.4999999999999 before rounding..?

error: Value of: round(precise_toast_bounds.CenterPoint().x())
  Actual: 423
Expected: round(shelf_bounds.right() + (root_bounds.width() -
shelf_bounds.width()) / 2.0)
Which is: 424
Shelf right bound: 47
Root width: 800
Shelf width: 47
Precise toast center x position: 423

I'm confused why this isn't deterministic but https://codereview.chromium.org/2391823004/ will fix this.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b407c4aba81c739c364901214ee203acda162281

commit b407c4aba81c739c364901214ee203acda162281
Author: gab <gab@chromium.org>
Date: Fri Oct 07 19:22:58 2016

Revert of Log extra information on weird ToastManagerTest.PositionWithVisibleLeftShelf flake. (patchset #1 id:20001 of https://codereview.chromium.org/2394483006/ )

Reason for revert:
https://codereview.chromium.org/2391823004/ will fix  http://crbug.com/650925  and can't land as-is (patch failure) because of this CL

Original issue's description:
> Log extra information on weird ToastManagerTest.PositionWithVisibleLeftShelf flake.
>
> BUG= 650925 
> TBR=sadrul
>
> Committed: https://crrev.com/d7cbf7ccc5f21177c925657fd50c688ca437526a
> Cr-Commit-Position: refs/heads/master@{#423635}

TBR=sadrul@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG= 650925 

Review-Url: https://codereview.chromium.org/2402763002
Cr-Commit-Position: refs/heads/master@{#423928}

[modify] https://crrev.com/b407c4aba81c739c364901214ee203acda162281/ash/system/toast/toast_manager_unittest.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/fbda6558904fcc065cfe88c47e3354a98b0b1d7b

commit fbda6558904fcc065cfe88c47e3354a98b0b1d7b
Author: yoshiki <yoshiki@chromium.org>
Date: Fri Oct 07 19:43:05 2016

Use EXPECT_NEAR to compare float values

This patch uses EXPECT_NEAR to compare float values, to prevent comparison error. Previously "round" function was used to compare, but it was the cause of flakiness (see the issue for detail).

BUG= 650925 
TEST=Run tests 5 times on Win bots and observe no failure.

Review-Url: https://codereview.chromium.org/2391823004
Cr-Commit-Position: refs/heads/master@{#423937}

[modify] https://crrev.com/fbda6558904fcc065cfe88c47e3354a98b0b1d7b/ash/system/toast/toast_manager_unittest.cc

Should be fixed, will re-open if it reflakes.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/d7cbf7ccc5f21177c925657fd50c688ca437526a

commit d7cbf7ccc5f21177c925657fd50c688ca437526a
Author: gab <gab@chromium.org>
Date: Thu Oct 06 19:42:20 2016

Log extra information on weird ToastManagerTest.PositionWithVisibleLeftShelf flake.

BUG= 650925 
TBR=sadrul

Review-Url: https://codereview.chromium.org/2394483006
Cr-Commit-Position: refs/heads/master@{#423635}

[modify] https://crrev.com/d7cbf7ccc5f21177c925657fd50c688ca437526a/ash/system/toast/toast_manager_unittest.cc

[Automated comment] removing mislabelled merge-merged-2840