Clean up webrtc external capture. This cl removes the dependency to the external capture module if external capturing is used in webrtc. It also removes two external capture methods that is not needed. Further more it adds I420VideoFrame::Create that takes a pointer to packed memory as input.
Clean up webrtc external capture.
This cl removes the dependency to the external capture module if external capturing is used in webrtc.
It also removes two external capture methods that is not needed.
Further more it adds I420VideoFrame::Create that takes a pointer to packed memory as input.

R=magjed@webrtc.org, mflodman@webrtc.org, pbos@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/43879004

Cr-Original-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#8804}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 9f9ea7e5abc3fa561e6b190b45219f2416c8786b

sippet/talk,dcpang/fatline-libjingle,sippet/talk,sippet/talk,sippet/talk,sippet/talk,dcpang/fatline-libjingle,dcpang/fatline-libjingle,dcpang/fatline-libjingle,dcpang/fatline-libjingle