Old NEON
LibYUVPlanarTest.TestGaussCol_Opt (916 ms)

New NEON
LibYUVPlanarTest.TestGaussCol_Opt (520 ms)

C vectorized
LibYUVPlanarTest.TestGaussCol_Opt (739 ms)

TBR=kjellander@chromium.org
BUG=libyuv:719
TEST=LibYUVPlanarTest.TestGaussCol_Opt

Change-Id: I863b66f700f7a71fcb08a2eabb03240fdaf8a238
Reviewed-on: https://chromium-review.googlesource.com/626938Reviewed-by: Cheng Wang <wangcheng@google.com>