Fix 2 regressions in video capture on Android.

This patch fixes 2 regressions in video capture on Android (introducded by recent code refactoring) as:
1. NV21 was treated as NV12.
2. Padding color for letterboxing should be black (y,u,v)=(0,128,128), instead of green (0,0,0).

BUG=322743
R=sheu@chromium.org

Review URL: https://codereview.chromium.org/111013002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@239794 0039d316-1c4b-4281-b951-d872f2087c98
Roll libjpeg_turbo to 239583.

This rolls in the temporary change to limit NO_GETENV to Android only.
Will roll to the version with the temporary change reverted tomorrow
after a canary build.

BUG=322228
TBR=

Review URL: https://codereview.chromium.org/108553004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@239795 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 239794
Update .DEPS.git

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@239796 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 239796