Problem has been introduced recently with the cleanup patch
I0816ec12ec0a6f21d0f25f10c214b5fd327afc6c

Change-Id: Iaacb956a6039eb5826b82618dc03be32053fb892

Change-Id: I27015ed57b4c4390cfde3d0eecd82c3e76fd3786

This commit changed the initialization of best_mode_index to -1 to make
sure it is not mistakenly used for mode masking.

Change-Id: I75b05db51466070dd23c4ee57a4d4b40764dc019

Change-Id: I08aa0c213df34c084eb7a3c51b6b3306e49c7757

This reverts commit 22a3e307

Change-Id: I460d905edf5fb2006da58c18fbe02c04d0c631bb

Change-Id: Ia4bef41a6b0252593ad84612a2a143c724fd03ea

Change-Id: I0462bf1ca1b4e5a1c06259979b4daff949b8a2c6

Change-Id: I1324c339815a47004ddccdaf651d24c60382b92f

Change-Id: I51c71dd4aee6592fb90feebcf864bccc87dacec6

Change-Id: Ie26b6ca8de733a527f820b16148e7a2231073f0f

Cleanup.

Change-Id: I54d989e24b35323cda7290654e425565d5c9ea2d

Change-Id: I721ff26e3d5dbef80b8cd2dd562adae3748f6687

Change-Id: I9be2e4e9aeda0fae6dc946deae2999be51daebe0

In mode selection loop, once mode_index pass mode_skip_start, all
modes with a different reference frame from current best mode are
masked out using mode_skip_mask.

However, the setting of mode_skip_mask may use an invalid mode if
there is no mode tested yet. This commit fixes the issue by making
sure a mode has been tested and selected. Otherwise, no mode will be
masked out because of their reference frame.

Change-Id: Ib0009e8a96836a65cf5347440fff8a2e1a67f29f

Change-Id: I9b8f9a3f4fa9d48695149dd68ecb5e8d84accafe

Change-Id: Idf612c772440158cd1645623241c51ab0d57405c