Rename some cricket::VideoFrame methods, to align with webrtc::VideoFrame.

GetVideoFrameBuffer --> video_frame_buffer
GetVideoRotation --> rotation
SetRotation --> set_rotation

BUG=webrtc:5682

Review URL: https://codereview.webrtc.org/1885443002

Cr-Original-Commit-Position: refs/heads/master@{#12342}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: f38687635426bb9b5c53d81367a1618f9555c3ef
11 files changed