[NORMATIVE] Enable NO_FRAME_CONTEXT_SIGNALING by default.

BUG=aomedia:1437

Change-Id: Ifdb65ff3b0447c8d16103eb9a628535b37cd0e9f

build/cmake/aom_config_defaults.cmake

diff --git a/build/cmake/aom_config_defaults.cmake b/build/cmake/aom_config_defaults.cmake
index 8b918ed..bf93767 100644
--- a/build/cmake/aom_config_defaults.cmake
+++ b/build/cmake/aom_config_defaults.cmake
@@ -113,7 +113,7 @@
 set(CONFIG_LOWPRECISION_BLEND 1 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_MAX_TILE 1 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_MONO_VIDEO 1 CACHE NUMBER "AV1 experiment flag.")
-set(CONFIG_NO_FRAME_CONTEXT_SIGNALING 0 CACHE NUMBER "AV1 experiment flag.")
+set(CONFIG_NO_FRAME_CONTEXT_SIGNALING 1 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_OBU_FRAME 0 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_OBU_NO_IVF 0 CACHE NUMBER "AV1 experiment flag.")
 set(CONFIG_OBU_SIZE_AFTER_HEADER 0 CACHE NUMBER "AV1 experiment flag.")