Rename TaskRunner::RunsTasksOnCurrentThread() in //third_party

renamed TaskRunner::RunsTasksOnCurrentThread() to
TaskRunner::RunsTasksInCurrentSequence() in //third_party

BUG=665062

Review-Url: https://codereview.chromium.org/2959613002
Cr-Commit-Position: refs/heads/master@{#482181}
9 files changed