Chrome Version: 51.0.2699.0 (Official Build) dev (64-bit)
Chrome OS Version: 8155.0.0 (Official Build) dev-channel link
Chrome OS Platform: Pixel
Network info: home dsl

Please specify Cr-* of the system to which this bug/feature applies (add
the label below).

Steps To Reproduce:
(1) Open a progressive web app that meets the criteria for 'add to homescreen' dialog <https://developer.chrome.com/multidevice/android/installtohomescreen>
(2) Visit the app twice, five minutes apart
(3)

Expected Result:
A dialog should appear giving the user the opportunity to add it to the list of apps.

Actual Result:
Nothing.

How frequently does this problem reproduce? (Always, sometimes, hard to
reproduce?)
Always

What is the impact to the user, and is there a workaround? If so, what is
it? Could add a bookmark, but can't see a way to add it to the list of apps.