Removes unused WaveOut APIs from ADM.

Will remove default implementations as well once landed and removed
in Chrome as well.

These two AudioDeviceModule APIs are removed:

int32_t SetWaveOutVolume(uint16_t volumeLeft, uint16_t volumeRight)
int32_t WaveOutVolume(uint16_t* volumeLeft, uint16_t* volumeRight) const

BUG=webrtc:7306

Review-Url: https://codereview.webrtc.org/3006793002
Cr-Original-Commit-Position: refs/heads/master@{#19581}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: ecf312e60356dd4df999a0675e7d1cf85e0dd495
24 files changed