GitLab

This changes the form of DoNothing() from a simple no-arg function to a class
that produces callbacks via templated operator().  This allows callers to
replace base::Bind(&base::DoNothing) with base::DoNothing() for a small
boilerplate reduction; more importantly, it allows using DoNothing() to replace
existing no-op functions/lambdas that took more than zero args, and thus had to
be manually declared.  This removes dozens of such functions and around 600 LOC
total.

In a few places, DoNothing() can't be used directly, and this change also adds
explicit callback-generating Once<>() and Repeatedly<>() members that will
produce a callback with a specific signature.

BUG=811554
TEST=none

Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_mojo;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_vr;master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
Change-Id: I37f87b35c6c079a6a8c03ff18ec3a54e1237f126
Reviewed-on: https://chromium-review.googlesource.com/903416
Commit-Queue: Peter Kasting <pkasting@chromium.org>
Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Reviewed-by: Gabriel Charette <gab@chromium.org>
Cr-Commit-Position: refs/heads/master@{#538953}