Reland "Allow AudioSendStream to reconfig AudioNetworkAdaptor"

BUG=b/63898232, b/64053465

Originally Reviewed-on: https://chromium-review.googlesource.com/584707

Reverted-on: https://chromium-review.googlesource.com/586268
Change-Id: I212b0c1e81a6ccd73b051e6728e601a8641463b8
Reviewed-on: https://chromium-review.googlesource.com/586328
Commit-Queue: Minyue Li <minyue@webrtc.org>
Reviewed-by: Michael T <tschumim@webrtc.org>
Reviewed-by: Fredrik Solenberg <solenberg@webrtc.org>
Cr-Original-Commit-Position: refs/heads/master@{#19153}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 8de1826b6d51830aacfcc0944e85584495369c70
2 files changed