This change also leaves in an opt-out setting (noIncrementalSync), just
in case we need to disable it at some point.
Change-Id: I3575efe942294b764c35d9259ce75d124b590e98
Reviewed-on: https://go-review.googlesource.com/c/tools/+/182468
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Cottrell <iancottrell@google.com>