Bug 1470554 - Revert ES6 arrow changes from bug 1468107 (#3708)
Bug 1470554 - Revert ES6 arrow changes from bug 1468107 (#3708)

Since the functions reference `this`, and switching to the ES6 arrow
function form changes the way `this` is bound, which caused the perf
alert buttons to no longer appear.

Partially reverts dcc0c4a529e6216c4a7631b9c1c332c57c62cb7e (#3646).
edmorley/treeherder,KWierso/treeherder,KWierso/treeherder,edmorley/treeherder,edmorley/treeherder,KWierso/treeherder,KWierso/treeherder,edmorley/treeherder