Bug
1648344 Part 1: Apply default viewport width in more circumstances, matching Chrome. r=hiro
Setting the effective max-width to the default viewport width value this way
matches Chrome behavior and improves web compatibility.
https://source.chromium.org/chromium/chromium/src/+/master:third_party/blink/renderer/core/page/viewport_description.cc;l=94-101;drc=
f668b0ef8c8813fd06387ec215a08f2df7dd1234?originalUrl=https:%2F%2Fcs.chromium.org%2F
Differential Revision: https://phabricator.services.mozilla.com/D84446