Store JSON perf results for low_bandwidth_audio_test.
Store JSON perf results for low_bandwidth_audio_test.

Bug: chromium:755660
Change-Id: I87c19f8dde14772e75f93c723f11408702ca8c8e
Reviewed-on: https://webrtc-review.googlesource.com/39515
Reviewed-by: Patrik Höglund <b486136ee68458b09c92c86c39f451c87d6ef6a1@webrtc.org>
Reviewed-by: Fredrik Solenberg <a86c06127c44de4932e34935a0755af178aabab6@webrtc.org>
Commit-Queue: Edward Lemur <d05609f027dc667cc37492b1dc1bdea5d60fa82a@webrtc.org>
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#21615}
ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc