Merge "Enable dual buffer rd search and encoding scheme"

diff --cc vp9/encoder/vp9_block.h
Simple merge

diff --cc vp9/encoder/vp9_encodeframe.c
Simple merge

diff --cc vp9/encoder/vp9_encodemb.c
Simple merge

diff --cc vp9/encoder/vp9_onyx_if.c
Simple merge

diff --cc vp9/encoder/vp9_rdopt.c
Simple merge