This Cl removes most calls to these methods on Windows and Linux:
- MessageLoop::PostTask
- MessageLoop::PostDelayedTask
- MessageLoop::ReleaseSoon
- MessageLoop::DeleteSoon
- MessageLoop::Run
- MessageLoop::RunUntilIdle

Also note that calls to thread->message_loop()->task_runner() have
been replaced with thread->task_runner() (|thread| is a base::Thread).

This CL was generated by running the clang-tidy checks available here
https://crbug.com/616447#c153 on Windows and Mac and by applying a few
manual fixes (e.g. to remove a call made from a macro in
audio_low_latency_input_win_unittest.cc).

BUG=616447
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_site_isolation

Review-Url: https://codereview.chromium.org/2211473003
Cr-Commit-Position: refs/heads/master@{#414442}