Deprecate no_show_fwd_kf flag

Its functionality has been subsumed by other controllers.

BUG=aomedia:3079

Change-Id: Ie3ff8059b4a1a4de748fe83972c64526ceab376e

av1/encoder/encode_strategy.c

diff --git a/av1/encoder/encode_strategy.c b/av1/encoder/encode_strategy.c
index c428308..b58dc45 100644
--- a/av1/encoder/encode_strategy.c
+++ b/av1/encoder/encode_strategy.c
@@ -339,10 +339,6 @@
     // no show frames are arf frames
     source = av1_lookahead_peek(cpi->ppi->lookahead, src_index,
                                 cpi->compressor_stage);
-    // When src_index == rc->frames_to_key, it indicates a fwd_kf
-    if (src_index == cpi->rc.frames_to_key && src_index != 0) {
-      cpi->no_show_fwd_kf = 1;
-    }
     if (source != NULL) {
       cm->showable_frame = 1;
     }
@@ -987,7 +983,6 @@
   if (frame_params->frame_type == KEY_FRAME) {
     // Don't do tpl for fwd key frames or fwd key frame overlays
     allow_tpl = allow_tpl && !cpi->sf.tpl_sf.disable_filtered_key_tpl &&
-                !cpi->no_show_fwd_kf &&
                 gf_group->update_type[cpi->gf_frame_index] != OVERLAY_UPDATE;
   } else {
     // Do tpl after ARF is filtered, or if no ARF, at the second frame of GF

av1/encoder/encoder.c

diff --git a/av1/encoder/encoder.c b/av1/encoder/encoder.c
index 6bafa34..a01d6f3 100644
--- a/av1/encoder/encoder.c
+++ b/av1/encoder/encoder.c
@@ -4296,9 +4296,6 @@
   if (oxcf->tile_cfg.enable_large_scale_tile)
     cm->features.refresh_frame_context = REFRESH_FRAME_CONTEXT_DISABLED;
 
-  // Initialize fields related to forward keyframes
-  cpi->no_show_fwd_kf = 0;
-
   if (assign_cur_frame_new_fb(cm) == NULL) return AOM_CODEC_ERROR;
 
 #if CONFIG_COLLECT_COMPONENT_TIMING

av1/encoder/encoder.h

diff --git a/av1/encoder/encoder.h b/av1/encoder/encoder.h
index 8fee6b1..336d638 100644
--- a/av1/encoder/encoder.h
+++ b/av1/encoder/encoder.h
@@ -2490,11 +2490,6 @@
   AV1EncoderConfig oxcf;
 
   /*!
-   * When set, this flag indicates that the current frame is a forward keyframe.
-   */
-  int no_show_fwd_kf;
-
-  /*!
    * Stores the trellis optimization type at segment level.
    * optimize_seg_arr[i] stores the trellis opt type for ith segment.
    */