Add temporary dummy mask for compound segmentation

This uses a segmentation mask (which is temporarily computed arbitrarily)
to blend predictors in compound prediction. The mask will be computed
using a color segmentation in a followup patch.
Change-Id: I2d24cf27a8589211f8a70779a5be2d61746406b9
diff --git a/av1/common/blockd.h b/av1/common/blockd.h
index 93d496e..cf646bf 100644
--- a/av1/common/blockd.h
+++ b/av1/common/blockd.h
@@ -180,10 +180,12 @@
           mode == NEAR_NEWMV || mode == NEW_NEARMV);
 }
 
-// TODO(sarahparker) this will eventually be extended when more
-// masked compound types are added
 static INLINE int is_masked_compound_type(COMPOUND_TYPE type) {
+#if CONFIG_COMPOUND_SEGMENT
+  return (type == COMPOUND_WEDGE || type == COMPOUND_SEG);
+#else
   return (type == COMPOUND_WEDGE);
+#endif  // CONFIG_COMPOUND_SEGMENT
 }
 #else
 
@@ -259,7 +261,10 @@
   COMPOUND_TYPE type;
   int wedge_index;
   int wedge_sign;
-  // TODO(sarahparker) add neccesary data for segmentation compound type
+#if CONFIG_COMPOUND_SEGMENT
+  int which;
+  uint8_t seg_mask[2][2 * MAX_SB_SQUARE];
+#endif  // CONFIG_COMPOUND_SEGMENT
 } INTERINTER_COMPOUND_DATA;
 #endif  // CONFIG_EXT_INTER