Mac AVfoundation: Change AVVideoScalingModeResizeAspect -> AVVideoScalingModeResizeAspectFill

Mac AVfoundation: Change AVVideoScalingModeResizeAspect -> AVVideoScalingModeResizeAspectFill

AVCaptureVideoDataOutput uses AVVideoScalingModeResizeAspect
to "Preserve aspect ratio of the source, and fill remaining areas
with black to fit destination dimensions." [1]. However, in at least
two cases, this seems to be problematic:
- When capturing 480p using a Blackmagic Ultra Studio Mini 
Recorder. (http://crbug.com/347371).
- When opening the camera in a 16:9 aspect ratio using 
AVFoundation _and then without closing it_ opening in a 4:3
aspect ratio with QTKit (http://crbug.com/357252).

The solution in both cases is to instruct the AVCaptureVideoDataOutput
to use AVVideoScalingModeResizeAspectFill: "Preserve aspect ratio of
the source, and crop picture to fit destination dimensions" [1].

[1] https://developer.apple.com/library/mac/documentation/AVFoundation/Reference/AVFoundation_Constants/Reference/reference.html#jumpTo_75

BUG=288562, 357252, 347371
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=261373

[mcasas, 2014-04-03 08:09:36]

tommi@ PTAL (minor patch)..
rsesek@ FYI.

[tommi (sloooow) - chröme, 2014-04-03 08:57:31]

lgtm

[mcasas, 2014-04-03 09:41:57]

The CQ bit was checked by mcasas@chromium.org

[commit-bot: I haz the power, 2014-04-03 09:43:35]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/mcasas@chromium.org/223513002/20001

[commit-bot: I haz the power, 2014-04-03 12:28:06]

Change committed as 261373