Adjust for initial cropping when adapting frame.

When adapting a frame, any initial cropping coordinate was replaced
by the coordinate calculated for adapting. Offset initial coordinate
instead.

BUG=webrtc:7880

Review-Url: https://codereview.webrtc.org/2975613002
Cr-Original-Commit-Position: refs/heads/master@{#19509}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 151aa6b3f7b00c9be05ffda848bc42748af19f04
3 files changed