INTERINTRA : adapt interintra_mode as cdf.

Use CDFs to code intrainter_mode instead of deprecated
tree coding.

AWCY, objective-1-fast, High Latency :
-0.02% all metrics, standard configuration

Change-Id: I839eec7cae9783e28d2018511989b7b56dc948a5
diff --git a/av1/decoder/decodemv.c b/av1/decoder/decodemv.c
index c457e2d..a37b940 100644
--- a/av1/decoder/decodemv.c
+++ b/av1/decoder/decodemv.c
@@ -192,9 +192,16 @@
 #if CONFIG_EXT_INTER && CONFIG_INTERINTRA
 static INTERINTRA_MODE read_interintra_mode(AV1_COMMON *cm, MACROBLOCKD *xd,
                                             aom_reader *r, int size_group) {
+#if CONFIG_EC_ADAPT
+  (void)cm;
+  const INTERINTRA_MODE ii_mode = (INTERINTRA_MODE)aom_read_symbol(
+      r, xd->tile_ctx->interintra_mode_cdf[size_group], INTERINTRA_MODES,
+      ACCT_STR);
+#else
   const INTERINTRA_MODE ii_mode = (INTERINTRA_MODE)aom_read_tree(
       r, av1_interintra_mode_tree, cm->fc->interintra_mode_prob[size_group],
       ACCT_STR);
+#endif
   FRAME_COUNTS *counts = xd->counts;
   if (counts) ++counts->interintra_mode[size_group][ii_mode];
   return ii_mode;