GitLab

A Lazy(Sequenced|SingleThread|COMSTA)TaskRunner lazily creates a TaskRunner.

A Lazy(Sequenced|SingleThread|COMSTA)TaskRunner is meant to be instantiated in
an anonymous namespace and used to post tasks to the same sequence/thread
from pieces of code that don't have a better way of sharing a TaskRunner.
Adding a Lazy(Sequenced|SingleThread|COMSTA)TaskRunner to an anonymous
namespace doesn't generate a static initializer.

Bug: 730170
Change-Id: Idb35cfe9a5ca5501b7057d7b90b9df3f702faff1
Reviewed-on: https://chromium-review.googlesource.com/524141
Commit-Queue: Francois Doray <fdoray@chromium.org>
Reviewed-by: Robert Liao <robliao@chromium.org>
Reviewed-by: Gabriel Charette <gab@chromium.org>
Cr-Commit-Position: refs/heads/master@{#478779}