Displays slow page max threshold on interventions internals NQ tab

Updates Network Quality tab with slow page max threshold.

Bug: 924574
Change-Id: Ia543e88115ac51f288b740bcc4992b3e3f65569e
Reviewed-on: https://chromium-review.googlesource.com/c/1430744
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Ryan Sturm <ryansturm@chromium.org>
Commit-Queue: Doug Arnett <dougarnett@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#627516}(cherry picked from commit ac27c056de3741e2265bb5a69aec8560d5c6b93a)
Reviewed-on: https://chromium-review.googlesource.com/c/1452069
Reviewed-by: Doug Arnett <dougarnett@chromium.org>
Cr-Commit-Position: refs/branch-heads/3683@{#162}
Cr-Branched-From: e51029943e0a38dd794b73caaf6373d5496ae783-refs/heads/master@{#625896}
6 files changed