Change old SmoothScroll.js listeners into passive.

Look at the function and determine if the listener is ssc_wheel
and use a passive listener instead.

See: https://docs.google.com/a/chromium.org/document/d/1yMAUU0wCeP7BIlQujqfwe3LBnG0QJaqymbkZwor9u60/edit?usp=sharing

BUG=501568

Change-Id: Idb7c522566d8873bd4a856f489e4baa15710ab06
Reviewed-on: https://chromium-review.googlesource.com/521343
Commit-Queue: David Tapuska <dtapuska@chromium.org>
Reviewed-by: Jeremy Roman <jbroman@chromium.org>
Reviewed-by: Rick Byers <rbyers@chromium.org>
Cr-Commit-Position: refs/heads/master@{#476654}
5 files changed