Chrome Version: 68.0.3405.0 (Official Build) unknown (32-bit)
OS: 10631.0.0 (Official Build) dev-channel scarlet

What steps will reproduce the problem?
(1) enter into the tablet mode
(2) open the browser window
(3) menu -> "more tools" -> "task manager"
(4) tap the back button in the shelf, after the task manager pops up

What is the expected result?
The task manager closes.

What happens instead?
Nothing happens

The task manager closes on Esc key. I think closing on the back button would be the consistent behavior on the tablet mode.


Please use labels and text to provide additional information.

If this is a regression (i.e., worked before), please consider using the
bisect tool (https://www.chromium.org/developers/bisect-builds-py) to help
us identify the root cause and more rapidly triage the issue.

For graphics-related bugs, please copy/paste the contents of the about:gpu
page at the end of this report.