VP8RandomBits2    196 third_party/libwebp/dec/frame.c           VP8RandomBits2(rg, DITHER_AMP_BITS + 1, amp) - DITHER_AMP_CENTER;
VP8RandomBits2     55 third_party/libwebp/utils/random.h   return VP8RandomBits2(rg, num_bits, rg->amp_);