Revert "Disable extended partitions on speed 6"

This reverts commit 8f4ea31d64a0318a8639f76aba5a20afda05a49a.

Reason for revert: Performance is worse than expected on hdres2

Change-Id: I02fcb513793e1cea70b868e0050c9f6337a768d1
diff --git a/av1/encoder/speed_features.c b/av1/encoder/speed_features.c
index b874232..ecd96a3 100644
--- a/av1/encoder/speed_features.c
+++ b/av1/encoder/speed_features.c
@@ -1089,7 +1089,7 @@
     sf->part_sf.prune_sub_8x8_partition_level =
         allow_screen_content_tools ? 0
                                    : frame_is_intra_only(&cpi->common) ? 1 : 2;
-    sf->part_sf.ext_partition_eval_thresh = BLOCK_128X128;
+    sf->part_sf.prune_part4_search = 3;
 
     sf->mv_sf.simple_motion_subpel_force_stop = FULL_PEL;
     sf->mv_sf.use_bsize_dependent_search_method = 1;
diff --git a/av1/encoder/speed_features.h b/av1/encoder/speed_features.h
index 04b681f..21c510d 100644
--- a/av1/encoder/speed_features.h
+++ b/av1/encoder/speed_features.h
@@ -438,8 +438,7 @@
   // Used if partition_search_type = FIXED_PARTITION
   BLOCK_SIZE fixed_partition_size;
 
-  // Prune extended partition types search based on the current partition type
-  // and the rdcost found in the subblocks.
+  // Prune extended partition types search
   // Can take values 0 - 2, 0 referring to no pruning, and 1 - 2 increasing
   // aggressiveness of pruning in order.
   int prune_ext_partition_types_search_level;
@@ -524,12 +523,10 @@
   // perform split/no_split decision on intra-frames.
   int intra_cnn_split;
 
-  // Disable extended partition search if the current bsize is greater than the
-  // threshold.
-  BLOCK_SIZE ext_partition_eval_thresh;
+  // Disable extended partition search for lower block sizes.
+  int ext_partition_eval_thresh;
 
-  // Prune extended partition search based on whether the split/rect partitions
-  // provided an improvement in the previous search.
+  // prune extended partition search
   // 0 : no pruning
   // 1 : prune 1:4 partition search using winner info from split partitions
   // 2 : prune 1:4 and AB partition search using split and HORZ/VERT info