Add support to base::Timer for custom task runners.

This patch adds a public method
SetTaskRunner(scoped_refptr<SingleThreadTaskRunner>) to base::Timer
which changes the task runner used by the timer
(ThreadTaskRunnerHandler::Get() by default).

This change will enable scheduling timers on the queues of the
Blink scheduler (see https://codereview.chromium.org/637303003/).
Most importantly, we plan to apply this to the shared timer in
blink::Platform.

BUG=

Review URL: https://codereview.chromium.org/637983003

Cr-Commit-Position: refs/heads/master@{#302947}


CrOS-Libchrome-Original-Commit: 7652da6d5cbd7e5b82b340e638ebe80aafeacf6e
4 files changed
tree: 174e380e9c7b381771eec73b1a34df2416831c8a
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/