Remove webrtc/base/buffer.cc, now that Chromium doesn't claim to need it anymore
Remove webrtc/base/buffer.cc, now that Chromium doesn't claim to need it anymore

BUG=webrtc:5845

Review-Url: https://codereview.webrtc.org/2477693002
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#14913}

ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc