WebRTC Audio private API: removing WebRtcAudioPrivate(Set/Get)ActiveSinkFunction
together with GetOutputControllers() logic from renderer hosts.

They are meant to be replaced with HTMLMediaElement's sinkId and setSinkId()

*PENDING on external change - do not submit yet*

BUG=647185,672468
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:closure_compilation;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/2784563003
Cr-Commit-Position: refs/heads/master@{#466312}
23 files changed