Backed out 8 changesets (bug 1561227) for causing browser_viewport_resizing_scrollbar.js to permafail CLOSED TREE

Backed out changeset aa00b1b62ea7 (bug 1561227)
Backed out changeset b22440a67078 (bug 1561227)
Backed out changeset 4776cec83ae8 (bug 1561227)
Backed out changeset ac88bbefb95f (bug 1561227)
Backed out changeset aef3cfa2f539 (bug 1561227)
Backed out changeset a3759e1a04e2 (bug 1561227)
Backed out changeset cfcf79794049 (bug 1561227)
Backed out changeset 97be65338edf (bug 1561227)

--HG--
rename : devtools/client/responsive/test/browser/browser_viewport_zoom_toggle.js => devtools/client/responsive/test/browser/browser_toggle_zoom.js