Make BLOCK_OFFSET marco operate in min tx_size
Make BLOCK_OFFSET marco operate in min tx_size

Change-Id: I99d3abd47480ebd73fc0034fac82663c003f7bb8

mbebenita/aom,smarter/aom,mbebenita/aom,luctrudeau/aom,smarter/aom,luctrudeau/aom,smarter/aom,GrokImageCompression/aom,GrokImageCompression/aom,mbebenita/aom,GrokImageCompression/aom,mbebenita/aom,GrokImageCompression/aom,luctrudeau/aom,mbebenita/aom,luctrudeau/aom,luctrudeau/aom,smarter/aom,GrokImageCompression/aom,GrokImageCompression/aom,mbebenita/aom,mbebenita/aom,smarter/aom,smarter/aom,luctrudeau/aom,mbebenita/aom,mbebenita/aom