Make the FakeWebRtcVideoCaptureModule class initialize frame data.
Make the FakeWebRtcVideoCaptureModule class initialize frame data.

Needed to avoid DrMemory warnings, if the frame is passed to libyuv
AVX assembly functions.

BUG=libyuv:377

Review-Url: https://codereview.webrtc.org/1985693002
Cr-Original-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#12765}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 744494f451e98680895f62e85388367dd73102a2

jchavanton/webrtc,jchavanton/webrtc,Alkalyne/webrtctrunk,Alkalyne/webrtctrunk,jchavanton/webrtc,jchavanton/webrtc,jchavanton/webrtc,jchavanton/webrtc,Alkalyne/webrtctrunk,Alkalyne/webrtctrunk,Alkalyne/webrtctrunk,Alkalyne/webrtctrunk,Alkalyne/webrtctrunk,Alkalyne/webrtctrunk,jchavanton/webrtc