By removing unnecessary fixed size buffer. BUG=webrtc:10276 Change-Id: I303303d8c4aa356372875abe6db5711cd10bcc71 Reviewed-on: https://webrtc-review.googlesource.com/c/120811 Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org> Reviewed-by: Niels Moller <nisse@webrtc.org> Commit-Queue: Per Kjellander <perkj@webrtc.org> Cr-Commit-Position: refs/heads/master@{#26509}