Note: This issue is also reproducible on build# 61.0.3135.5 (clang).

Is this Windows only? Also it seems that the action menu opens towards the right, when there is no space to open towards either the left or the right. Maybe that logic can be slightly smarter to open towards the direction where there is more space (even if it is not enough).

@calamity: Is this going to be affected by https://codereview.chromium.org/2951703002?

This just requires a logic change to getStartPointWithAnchor. I'll submit a follow-up patch to the current one. This is definitely a good case to fix.

With response to comment#4: Yes, This is Windows specific issue. This issue is not observed on Mac and Linux OS.

Unable to narrow down as issue is not observed on Chromium builds. Hence providing change-log URL.

Change Log URL:
https://chromium.googlesource.com/chromium/src/+log/60.0.3089.0..60.0.3090.0?pretty=fuller&n=10000

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/98e223c3c437db7740a771918a69869a91d79f91

commit 98e223c3c437db7740a771918a69869a91d79f91
Author: calamity <calamity@chromium.org>
Date: Mon Jul 03 03:59:49 2017

[cr-action-menu] Constrain menu to viewport.

This CL forces the action menu to align to the viewport after choosing
an anchor direction.

BUG= 734984 
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2948973002
Cr-Commit-Position: refs/heads/master@{#483938}

[modify] https://crrev.com/98e223c3c437db7740a771918a69869a91d79f91/chrome/test/data/webui/cr_elements/cr_action_menu_test.js
[modify] https://crrev.com/98e223c3c437db7740a771918a69869a91d79f91/ui/webui/resources/cr_elements/cr_action_menu/cr_action_menu.js

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/87be8f4c1eaef26b7c6d7ddb2c56d84ef504a232

commit 87be8f4c1eaef26b7c6d7ddb2c56d84ef504a232
Author: calamity <calamity@chromium.org>
Date: Mon Jul 10 03:41:35 2017

[cr-action-menu] Use clientWidth for rtl flipping.

This CL fixes a bug where the action menu would use the entire body's
length as the viewport when flipping coordinates in RTL.

It also moves the scroll position saving into showAtPosition so that
both show methods account for scroll correctly.

BUG= 734984 
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2966163004
Cr-Commit-Position: refs/heads/master@{#485181}

[modify] https://crrev.com/87be8f4c1eaef26b7c6d7ddb2c56d84ef504a232/chrome/test/data/webui/cr_elements/cr_action_menu_test.js
[modify] https://crrev.com/87be8f4c1eaef26b7c6d7ddb2c56d84ef504a232/ui/webui/resources/cr_elements/cr_action_menu/cr_action_menu.js

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1657a919ecc63f457d2c4049d58574fe2e7271d5

commit 1657a919ecc63f457d2c4049d58574fe2e7271d5
Author: calamity <calamity@chromium.org>
Date: Mon Jul 10 05:14:40 2017

Revert of [cr-action-menu] Use clientWidth for rtl flipping. (patchset #2 id:60001 of https://codereview.chromium.org/2966163004/ )

Reason for revert:
Breaks on https://uberchromegw.corp.google.com/i/chromium.mac/builders/Mac10.11%20Tests/builds/15007

Original issue's description:
> [cr-action-menu] Use clientWidth for rtl flipping.
>
> This CL fixes a bug where the action menu would use the entire body's
> length as the viewport when flipping coordinates in RTL.
>
> It also moves the scroll position saving into showAtPosition so that
> both show methods account for scroll correctly.
>
> BUG= 734984 
> CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation
>
> Review-Url: https://codereview.chromium.org/2966163004
> Cr-Commit-Position: refs/heads/master@{#485181}
> Committed: https://chromium.googlesource.com/chromium/src/+/87be8f4c1eaef26b7c6d7ddb2c56d84ef504a232

TBR=dpapad@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG= 734984 

Review-Url: https://codereview.chromium.org/2980463002
Cr-Commit-Position: refs/heads/master@{#485189}

[modify] https://crrev.com/1657a919ecc63f457d2c4049d58574fe2e7271d5/chrome/test/data/webui/cr_elements/cr_action_menu_test.js
[modify] https://crrev.com/1657a919ecc63f457d2c4049d58574fe2e7271d5/ui/webui/resources/cr_elements/cr_action_menu/cr_action_menu.js

 Issue 738867  has been merged into this issue.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/30fc850ad1f90068d6dcb4733870aa4ebc94cdc6

commit 30fc850ad1f90068d6dcb4733870aa4ebc94cdc6
Author: calamity <calamity@chromium.org>
Date: Tue Jul 11 10:30:11 2017

[cr-action-menu] Use clientWidth for rtl flipping.

This CL fixes a bug where the action menu would use the entire body's
length as the viewport when flipping coordinates in RTL.

It also moves the scroll position saving into showAtPosition so that
both show methods account for scroll correctly.

BUG= 734984 
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2966163004
Cr-Original-Commit-Position: refs/heads/master@{#485181}
Committed: https://chromium.googlesource.com/chromium/src/+/87be8f4c1eaef26b7c6d7ddb2c56d84ef504a232
Review-Url: https://codereview.chromium.org/2966163004
Cr-Commit-Position: refs/heads/master@{#485578}

[modify] https://crrev.com/30fc850ad1f90068d6dcb4733870aa4ebc94cdc6/chrome/test/data/webui/cr_elements/cr_action_menu_test.js
[modify] https://crrev.com/30fc850ad1f90068d6dcb4733870aa4ebc94cdc6/ui/webui/resources/cr_elements/cr_action_menu/cr_action_menu.js