Able to reproduce the issue on Ubuntu 14.04 using chrome latest Dev M52-52.0.2743.3. Observed unwanted scrollbar in the task manager when less number of tasks present.

I can't reproduce. Does this happen for you with a fresh profile?

I'm not sure why this is happening, it might be that the WM is remembering the last size for this window. The process titles are absurdly narrow here. If this is only a problem on Linux, it's lower priority.

I think I've seen this on Windows too, in the context of browsertests at least: opening the task manager during a test results in too-small windows, and the "Tasks" column never seems wide enough. I tend to forget about it, since the window size is persisted as a preference, so I don't encounter it on my main profile.

Sorry for the late response to comment #2:

Checked the issue on 53.0.2761.2 dev, Ubuntu 14.04 by creating a fresh profile. Issue is still reproducible. i.e; Unwanted vertical scroll bar is seen even when there are less number of tasks.

Attaching screen shot of same.

Deleted: Issue_614317.png 133 KB

	Issue_614317.png 133 KB View Download

punting

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/6678470d3169979d811eec56e7cdea668ab751c1

commit 6678470d3169979d811eec56e7cdea668ab751c1
Author: estade <estade@chromium.org>
Date: Tue Oct 04 19:54:39 2016

Fix task manager's default sizing.

Set default width based on contents rather than hardcoding a value (which happened to be too small once we adjusted outer padding for the dialog).

BUG= 614317 

Review-Url: https://codereview.chromium.org/2344703002
Cr-Commit-Position: refs/heads/master@{#422893}

[modify] https://crrev.com/6678470d3169979d811eec56e7cdea668ab751c1/chrome/browser/ui/views/task_manager_view.cc
[modify] https://crrev.com/6678470d3169979d811eec56e7cdea668ab751c1/chrome/browser/ui/views/task_manager_view.h
[modify] https://crrev.com/6678470d3169979d811eec56e7cdea668ab751c1/ui/views/controls/scroll_view.cc
[modify] https://crrev.com/6678470d3169979d811eec56e7cdea668ab751c1/ui/views/controls/table/table_view.cc
[modify] https://crrev.com/6678470d3169979d811eec56e7cdea668ab751c1/ui/views/controls/table/table_view.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/cc9948e8ed03ea9230047ced2e8167afb873c7a4

commit cc9948e8ed03ea9230047ced2e8167afb873c7a4
Author: thestig <thestig@chromium.org>
Date: Wed Oct 05 00:40:45 2016

Revert of Fix task manager's default sizing. (patchset #6 id:100001 of https://codereview.chromium.org/2344703002/ )

Reason for revert:
On Linux, the task manager window self expands and gets wider and wiser.

Original issue's description:
> Fix task manager's default sizing.
>
> Set default width based on contents rather than hardcoding a value (which happened to be too small once we adjusted outer padding for the dialog).
>
> BUG= 614317 
>
> Committed: https://crrev.com/6678470d3169979d811eec56e7cdea668ab751c1
> Cr-Commit-Position: refs/heads/master@{#422893}

TBR=sky@chromium.org,estade@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG= 614317 

Review-Url: https://codereview.chromium.org/2389803006
Cr-Commit-Position: refs/heads/master@{#423023}

[modify] https://crrev.com/cc9948e8ed03ea9230047ced2e8167afb873c7a4/chrome/browser/ui/views/task_manager_view.cc
[modify] https://crrev.com/cc9948e8ed03ea9230047ced2e8167afb873c7a4/chrome/browser/ui/views/task_manager_view.h
[modify] https://crrev.com/cc9948e8ed03ea9230047ced2e8167afb873c7a4/ui/views/controls/scroll_view.cc
[modify] https://crrev.com/cc9948e8ed03ea9230047ced2e8167afb873c7a4/ui/views/controls/table/table_view.cc
[modify] https://crrev.com/cc9948e8ed03ea9230047ced2e8167afb873c7a4/ui/views/controls/table/table_view.h