Add kf_ctx experimental flag

Change-Id: Ib0d699106583e7072e6287a5a780967b5059efa3
diff --git a/build/cmake/aom_config_defaults.cmake b/build/cmake/aom_config_defaults.cmake
index 09ec0fe..e2e2c7b 100644
--- a/build/cmake/aom_config_defaults.cmake
+++ b/build/cmake/aom_config_defaults.cmake
@@ -157,6 +157,7 @@
 set(CONFIG_INTRA_EDGE 1 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_INTRA_INTERP 0 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_JNT_COMP 0 CACHE NUMBER "AV1 experiment flag.")
+set(CONFIG_KF_CTX 0 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_LGT 0 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_LOOPFILTERING_ACROSS_TILES 1 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_LOOPFILTER_LEVEL 0 CACHE NUMBER "AV1 experiment flag.")
diff --git a/configure b/configure
index 17a8f66..35c7fb9 100755
--- a/configure
+++ b/configure
@@ -285,6 +285,7 @@
     inter_stats_only
     palette_delta_encoding
     rawbits
+    kf_ctx
     pvq
     cfl
     xiphrc