Disable BT.709 to BT.601 conversion by default.

gpu/ipc/service/direct_composition_surface_win.cc

Index: gpu/ipc/service/direct_composition_surface_win.cc
diff --git a/gpu/ipc/service/direct_composition_surface_win.cc b/gpu/ipc/service/direct_composition_surface_win.cc
index ac184e96e62625f2d9ebf3fb886cc2998e6d0867..c6b573750d8e78c40baa3426f7133254533eceb5 100644
--- a/gpu/ipc/service/direct_composition_surface_win.cc
+++ b/gpu/ipc/service/direct_composition_surface_win.cc
@@ -47,7 +47,7 @@ namespace {
 // Some drivers fail to correctly handle BT.709 video in overlays. This flag
 // converts them to BT.601 in the video processor.
 const base::Feature kFallbackBT709VideoToBT601{
-    "FallbackBT709VideoToBT601", base::FEATURE_ENABLED_BY_DEFAULT};
+    "FallbackBT709VideoToBT601", base::FEATURE_DISABLED_BY_DEFAULT};
 
 // This class is used to make sure a specified surface isn't current, and upon
 // destruction it will make the surface current again if it had been before.