The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/cb2dd32558ee6ebbaa2a11a607f8d7aa8ae535fe

commit cb2dd32558ee6ebbaa2a11a607f8d7aa8ae535fe
Author: Nicolas Ouellet-payeur <nicolaso@chromium.org>
Date: Wed Jul 18 21:23:43 2018

In chrome://discards, add 'Can Freeze?'/'Can Discard?' columns

The 'Can Discard?' column indicates proactive discards, not urgent discards.

Each cell in those columns shows a checkmark or crossmark, with a
'[View Reason]' link. Hovering the link shows a tooltip with the reasons why
it can't be frozen/discarded.

The 'View Reason' button is disabled if the tab _can_ be frozen/discarded, since
there are no failure reasons to show.

Also, remove the 'Media' column, since it's redundant now.

Screenshot (apologies for external contributors):
https://screenshot.googleplex.com/n9oDCgM3ffj

Bug:  864149 
Cq-Include-Trybots: luci.chromium.try:closure_compilation
Change-Id: Ied07835a5eae7a80989226a3662dc12d3e9ee9b2
Reviewed-on: https://chromium-review.googlesource.com/1140368
Commit-Queue: Sébastien Marchand <sebmarchand@chromium.org>
Reviewed-by: Chris Hamilton <chrisha@chromium.org>
Reviewed-by: Sébastien Marchand <sebmarchand@chromium.org>
Reviewed-by: Ken Buchanan <kenrb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#576216}
[modify] https://crrev.com/cb2dd32558ee6ebbaa2a11a607f8d7aa8ae535fe/chrome/browser/resource_coordinator/tab_lifecycle_unit.cc
[modify] https://crrev.com/cb2dd32558ee6ebbaa2a11a607f8d7aa8ae535fe/chrome/browser/resource_coordinator/tab_lifecycle_unit_unittest.cc
[modify] https://crrev.com/cb2dd32558ee6ebbaa2a11a607f8d7aa8ae535fe/chrome/browser/resources/discards/discards.css
[modify] https://crrev.com/cb2dd32558ee6ebbaa2a11a607f8d7aa8ae535fe/chrome/browser/resources/discards/discards.html
[modify] https://crrev.com/cb2dd32558ee6ebbaa2a11a607f8d7aa8ae535fe/chrome/browser/resources/discards/discards.js
[modify] https://crrev.com/cb2dd32558ee6ebbaa2a11a607f8d7aa8ae535fe/chrome/browser/ui/webui/discards/discards.mojom
[modify] https://crrev.com/cb2dd32558ee6ebbaa2a11a607f8d7aa8ae535fe/chrome/browser/ui/webui/discards/discards_ui.cc
[modify] https://crrev.com/cb2dd32558ee6ebbaa2a11a607f8d7aa8ae535fe/chrome/test/data/webui/discards/discards_browsertest.js

sebmarchand@, can we mark this issue fixed?

Yep!