Make tile dependency experiment work with ext tile.

* Add tile dependency support when ext tile enabled.

Change-Id: I8fe40adf285e171b5b761b15590a8b1c6758b8f7

av1/encoder/bitstream.c

@@ -3674,6 +3674,9 @@ static void write_tile_info(const AV1_COMMON *const cm,
     aom_wb_write_literal(wb, tile_width - 1, 6);
     aom_wb_write_literal(wb, tile_height - 1, 6);
   }
+#if CONFIG_DEPENDENT_HORZTILES
+  if (tile_height > 1) aom_wb_write_bit(wb, cm->dependent_horz_tiles);
+#endif
 #else
   int min_log2_tile_cols, max_log2_tile_cols, ones;
   av1_get_tile_n_bits(cm->mi_cols, &min_log2_tile_cols, &max_log2_tile_cols);
@@ -3687,11 +3690,10 @@ static void write_tile_info(const AV1_COMMON *const cm,
   // rows
   aom_wb_write_bit(wb, cm->log2_tile_rows != 0);
   if (cm->log2_tile_rows != 0) aom_wb_write_bit(wb, cm->log2_tile_rows != 1);
-#endif  // CONFIG_EXT_TILE
-
 #if CONFIG_DEPENDENT_HORZTILES
   if (cm->log2_tile_rows != 0) aom_wb_write_bit(wb, cm->dependent_horz_tiles);
 #endif
+#endif  // CONFIG_EXT_TILE
 
 #if CONFIG_LOOPFILTERING_ACROSS_TILES
   aom_wb_write_bit(wb, cm->loop_filter_across_tiles_enabled);

av1/encoder/encoder.c

@@ -879,7 +879,11 @@ static void set_tile_info(AV1_COMP *cpi) {
 
 #if CONFIG_DEPENDENT_HORZTILES
   cm->dependent_horz_tiles = cpi->oxcf.dependent_horz_tiles;
+#if CONFIG_EXT_TILE
+  if (cm->tile_rows <= 1) cm->dependent_horz_tiles = 0;
+#else
   if (cm->log2_tile_rows == 0) cm->dependent_horz_tiles = 0;
+#endif
 #if CONFIG_TILE_GROUPS
   if (cpi->oxcf.mtu == 0) {
     cm->num_tg = cpi->oxcf.num_tile_groups;