Remove experimental flag of WARPED_MOTION

This experiment has been adopted, we can simplify the code
by dropping the associated preprocessor conditionals.

Change-Id: I54fee8a18afaec5333ae852eb6bd9ac0e2550db1
diff --git a/av1/common/blockd.h b/av1/common/blockd.h
index 4bbd828..4ae3a9e 100644
--- a/av1/common/blockd.h
+++ b/av1/common/blockd.h
@@ -377,10 +377,8 @@
   int mi_row;
   int mi_col;
 #endif
-#if CONFIG_WARPED_MOTION
   int num_proj_ref[2];
   WarpedMotionParams wm_params[2];
-#endif  // CONFIG_WARPED_MOTION
 
 #if CONFIG_CFL
   // Index of the alpha Cb and alpha Cr combination
@@ -1399,10 +1397,7 @@
 
 static INLINE MOTION_MODE
 motion_mode_allowed(int block, const WarpedMotionParams *gm_params,
-#if CONFIG_WARPED_MOTION
-                    const MACROBLOCKD *xd,
-#endif
-                    const MODE_INFO *mi) {
+                    const MACROBLOCKD *xd, const MODE_INFO *mi) {
   const MB_MODE_INFO *mbmi = &mi->mbmi;
 #if CONFIG_AMVR
   if (xd->cur_frame_force_integer_mv == 0) {
@@ -1416,7 +1411,6 @@
       is_inter_mode(mbmi->mode) && mbmi->ref_frame[1] != INTRA_FRAME &&
       is_motion_variation_allowed_compound(mbmi)) {
     if (!check_num_overlappable_neighbors(mbmi)) return SIMPLE_TRANSLATION;
-#if CONFIG_WARPED_MOTION
     if (!has_second_ref(mbmi) && mbmi->num_proj_ref[0] >= 1 &&
         !av1_is_scaled(&(xd->block_refs[0]->sf))) {
 #if CONFIG_AMVR
@@ -1427,7 +1421,6 @@
       return WARPED_CAUSAL;
     }
 
-#endif  // CONFIG_WARPED_MOTION
 #if CONFIG_NCOBMC_ADAPT_WEIGHT
     if (ncobmc_mode_allowed_bsize(mbmi->sb_type) < NO_OVERLAP)
       return NCOBMC_ADAPT_WEIGHT;
@@ -1441,16 +1434,10 @@
 
 static INLINE void assert_motion_mode_valid(MOTION_MODE mode, int block,
                                             const WarpedMotionParams *gm_params,
-#if CONFIG_WARPED_MOTION
                                             const MACROBLOCKD *xd,
-#endif
                                             const MODE_INFO *mi) {
   const MOTION_MODE last_motion_mode_allowed =
-      motion_mode_allowed(block, gm_params,
-#if CONFIG_WARPED_MOTION
-                          xd,
-#endif
-                          mi);
+      motion_mode_allowed(block, gm_params, xd, mi);
 
   // Check that the input mode is not illegal
   if (last_motion_mode_allowed < mode)