Before
I420ToARGB_Opt (594 ms)
I422ToARGB_Opt (483 ms)
I411ToARGB_Opt (748 ms) ***
I444ToARGB_Opt (452 ms)
I400ToARGB_Opt (218 ms)

After
I420ToARGB_Opt (591 ms)
I422ToARGB_Opt (454 ms)
I411ToARGB_Opt (502 ms)  ***
I444ToARGB_Opt (441 ms)
I400ToARGB_Opt (216 ms)

TBR=harryjin@google.com
BUG=libyuv:525

Review URL: https://codereview.chromium.org/1459513002 .