--- a/gfx/thebes/gfxPrefs.h
+++ b/gfx/thebes/gfxPrefs.h
@@ -338,16 +338,17 @@ private:
DECL_GFX_PREF(Live, "apz.y_skate_highmem_adjust", APZYSkateHighMemAdjust, float, 0.0f);
DECL_GFX_PREF(Live, "apz.y_skate_size_multiplier", APZYSkateSizeMultiplier, float, 2.5f);
DECL_GFX_PREF(Live, "apz.y_stationary_size_multiplier", APZYStationarySizeMultiplier, float, 3.5f);
DECL_GFX_PREF(Live, "apz.zoom_animation_duration_ms", APZZoomAnimationDuration, int32_t, 250);
DECL_GFX_PREF(Live, "apz.scale_repaint_delay_ms", APZScaleRepaintDelay, int32_t, 500);
DECL_GFX_PREF(Live, "browser.ui.zoom.force-user-scalable", ForceUserScalable, bool, false);
DECL_GFX_PREF(Live, "browser.viewport.desktopWidth", DesktopViewportWidth, int32_t, 980);
+ DECL_GFX_PREF(Live, "browser.ui.scroll-toolbar-threshold", ToolbarScrollThreshold, float, 0.10f);
DECL_GFX_PREF(Live, "dom.ipc.plugins.asyncdrawing.enabled", PluginAsyncDrawingEnabled, bool, false);
DECL_GFX_PREF(Live, "dom.meta-viewport.enabled", MetaViewportEnabled, bool, false);
DECL_GFX_PREF(Once, "dom.vr.enabled", VREnabled, bool, false);
DECL_GFX_PREF(Live, "dom.vr.navigation.timeout", VRNavigationTimeout, int32_t, 1000);
DECL_GFX_PREF(Once, "dom.vr.oculus.enabled", VROculusEnabled, bool, true);
DECL_GFX_PREF(Once, "dom.vr.openvr.enabled", VROpenVREnabled, bool, false);
DECL_GFX_PREF(Once, "dom.vr.osvr.enabled", VROSVREnabled, bool, false);