[Android] Add a flag to disable the pull-to-refresh effect
Some people may not like pull-to-refresh. Some people may not like our
implementation of pull-to-reresh. Some people may not like refreshing
at all. Let's accomodate such users with a disabling override,
particularly now as we're experimenting with the initial version of the
effect.
The flag also allows for experiments gauging accidental activation and
other potentially negative side-effects.
Also remove the kEnableOverscrollNotifications flag; overscroll
notifications are now bundled with event acks, creating
minimal extra overhead for non-consuming platforms.
BUG=428429
Review URL: https://codereview.chromium.org/733293002
Cr-Commit-Position: refs/heads/master@{#305154}
16 files changed
