Move functionality out from AudioFrame and into AudioFrameOperations.

This CL is in preparation to move the AudioFrame into webrtc/api. The
AudioFrame is a POD type used for representing 10ms of audio. It
appears as a parameter and return value of interfaces being migrated
to webrtc/api, in particular AudioMixer.

Here, methods operator+=, operator>>=, Mute are
moved into a new target webrtc/audio/utility/audio_frame_operations,
and dependencies are changed to use
the new versions. The old AudioFrame methods are marked deprecated.

The audio frame utilities in webrtc/modules/utility:audio_frame_operations
are also moved to the new location.

TBR=kjellander@webrtc.org
BUG=webrtc:6548
NOPRESUBMIT=True

Review-Url: https://codereview.webrtc.org/2424173003
Cr-Original-Commit-Position: refs/heads/master@{#15413}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 6321b49a0da3ebdeede1430aa9bc825855646b79
28 files changed