yamaguchi@,

This regression was caused by the change of layer order of file list and empty folder UI.
Simple 1-line change (pointer-events:none on #empty-folder) should fix the issue, but now I think that placing the empty dialog UI behind the file list (as before) is more natural and safer.

Is there any workaround to keep the background color of file list transparent even with the new overlay scrollbar?
If there is not good workaround for it, I'll go with pointer-events:none solution.

For M-57, I'll revert the change (https://codereview.chromium.org/2652413002/
assuming that the revert of overlay scrollbar (https://codereview.chromium.org/2657143002/) fixes the  issue 685106 .

For the long-term solution, I want yamaguchi@'s investigation on the workaround.
Thanks in advance! 

The background was made to have solid color for workaround crbug/671644.
We have alternative workaround (add will-change: transform to the style), but it'll deny the LCD anti-aliasing of texts inside. Therefore I think pointer-events:none would be a reasonable solution at the moment.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/8fbb4032d36b3ae10373db8d489a0f9276cc5d54

commit 8fbb4032d36b3ae10373db8d489a0f9276cc5d54
Author: fukino <fukino@chromium.org>
Date: Mon Jan 30 06:59:01 2017

Revert of Files app: Correct the order of file-list layer and empty-folder layer. (patchset #1 id:1 of https://codereview.chromium.org/2652413002/ )

Reason for revert:
This change causes a regression  crbug.com/686618 .

Original issue's description:
> Files app: Correct the order of file-list layer and empty-folder layer.
>
> The UI indicating that the folder is empty is behind the file-list layer.
> It used to be visible because the file-list has transparent background, but with
> https://codereview.chromium.org/2554433002, file-list got background color and
> the UI turned invisible.
> We should correct the order of layers instead of reverting the background color
> of file list, as the background color of file list is necessary to make use of
> native overlay scrollbar.
>
> BUG= 685106 
> TEST=manually tested
> CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation
>
> Review-Url: https://codereview.chromium.org/2652413002
> Cr-Commit-Position: refs/heads/master@{#446280}
> Committed: https://chromium.googlesource.com/chromium/src/+/1d0085691a3932c3e299c4af35f71e6e97dc3222

TBR=yamaguchi@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG= 685106 , 686618 

Review-Url: https://codereview.chromium.org/2659313002
Cr-Commit-Position: refs/heads/master@{#446961}

[modify] https://crrev.com/8fbb4032d36b3ae10373db8d489a0f9276cc5d54/ui/file_manager/file_manager/main.html

I'll request a merge to M57, once https://codereview.chromium.org/2657143002/ lands on it.

Still see it on M57-Chrome OS 9202.12.0, 57.0.2987.19. please merge it to M57.

I'd like to merge the change in comment #8 to M57 to fix this issue.

This bug requires manual review: Reverts referenced in bugdroid comments after merge request.
Please contact the milestone owner if you have questions.
Owners: amineer@(clank), cmasso@(bling), ketakid@(cros), govind@(desktop)

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Approving merge to M57 Chrome OS.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/c1836bb99563be3c67db606dbfacd5c719499a2e

commit c1836bb99563be3c67db606dbfacd5c719499a2e
Author: Naoki Fukino <fukino@chromium.org>
Date: Mon Feb 06 05:29:28 2017

Revert of Files app: Correct the order of file-list layer and empty-folder layer. (patchset #1 id:1 of https://codereview.chromium.org/2652413002/ )

Reason for revert:
This change causes a regression  crbug.com/686618 .

Original issue's description:
> Files app: Correct the order of file-list layer and empty-folder layer.
>
> The UI indicating that the folder is empty is behind the file-list layer.
> It used to be visible because the file-list has transparent background, but with
> https://codereview.chromium.org/2554433002, file-list got background color and
> the UI turned invisible.
> We should correct the order of layers instead of reverting the background color
> of file list, as the background color of file list is necessary to make use of
> native overlay scrollbar.
>
> BUG= 685106 
> TEST=manually tested
> CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation
>
> Review-Url: https://codereview.chromium.org/2652413002
> Cr-Commit-Position: refs/heads/master@{#446280}
> Committed: https://chromium.googlesource.com/chromium/src/+/1d0085691a3932c3e299c4af35f71e6e97dc3222

TBR=yamaguchi@chromium.org
BUG= 685106 , 686618 

Review-Url: https://codereview.chromium.org/2659313002
Cr-Commit-Position: refs/heads/master@{#446961}
(cherry picked from commit 8fbb4032d36b3ae10373db8d489a0f9276cc5d54)

Review-Url: https://codereview.chromium.org/2677023002 .
Cr-Commit-Position: refs/branch-heads/2987@{#317}
Cr-Branched-From: ad51088c0e8776e8dcd963dbe752c4035ba6dab6-refs/heads/master@{#444943}

[modify] https://crrev.com/c1836bb99563be3c67db606dbfacd5c719499a2e/ui/file_manager/file_manager/main.html

 Issue 691686  has been merged into this issue.