Auto merge of #14999 - Manishearth:stylo-prefs, r=heycam

stylo: Hook property parsing into Gecko prefs

r=heycam, https://bugzilla.mozilla.org/show_bug.cgi?id=1297322

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This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/14999)
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5 files changed, 820 insertions, 25 deletions

diff --git a/components/style/build_gecko.rs b/components/style/build_gecko.rs
index 0420b498a73..6a524f6ddc0 100644
--- a/components/style/build_gecko.rs
+++ b/components/style/build_gecko.rs
@@ -226,6 +226,7 @@ mod bindings {
                 ..CodegenConfig::nothing()
             })
             .header(add_include("nsStyleStruct.h"))
+            .include(add_include("mozilla/ServoPropPrefList.h"))
             .header(add_include("mozilla/StyleAnimationValue.h"))
             .include(add_include("gfxFontConstants.h"))
             .include(add_include("nsThemeConstants.h"))
@@ -251,7 +252,8 @@ mod bindings {
             "NS_STYLE_.*",
             "NS_RADIUS_.*",
             "BORDER_COLOR_.*",
-            "BORDER_STYLE_.*"
+            "BORDER_STYLE_.*",
+            "mozilla::SERVO_PREF_.*",
         ];
         let whitelist = [
             "RawGecko.*",
diff --git a/components/style/gecko_bindings/bindings.rs b/components/style/gecko_bindings/bindings.rs
index b5c454db594..2f8a6aa9c34 100644
--- a/components/style/gecko_bindings/bindings.rs
+++ b/components/style/gecko_bindings/bindings.rs
@@ -757,6 +757,9 @@ extern "C" {
                                                               *mut nsCSSValueSharedList);
 }
 extern "C" {
+    pub fn Gecko_PropertyId_IsPrefEnabled(id: nsCSSPropertyID) -> bool;
+}
+extern "C" {
     pub fn Gecko_Construct_Default_nsStyleFont(ptr: *mut nsStyleFont,
                                                pres_context:
                                                    RawGeckoPresContextBorrowed);
diff --git a/components/style/gecko_bindings/structs_debug.rs b/components/style/gecko_bindings/structs_debug.rs
index daf706f3353..19635b1e959 100644
--- a/components/style/gecko_bindings/structs_debug.rs
+++ b/components/style/gecko_bindings/structs_debug.rs
@@ -1052,6 +1052,378 @@ pub mod root {
     pub mod mozilla {
         #[allow(unused_imports)]
         use self::super::super::root;
+        pub const SERVO_PREF_ENABLED_align_content: bool = false;
+        pub const SERVO_PREF_ENABLED_align_items: bool = false;
+        pub const SERVO_PREF_ENABLED_align_self: bool = false;
+        pub const SERVO_PREF_ENABLED_all: bool = true;
+        pub const SERVO_PREF_ENABLED_animation: bool = false;
+        pub const SERVO_PREF_ENABLED_animation_delay: bool = false;
+        pub const SERVO_PREF_ENABLED_animation_direction: bool = false;
+        pub const SERVO_PREF_ENABLED_animation_duration: bool = false;
+        pub const SERVO_PREF_ENABLED_animation_fill_mode: bool = false;
+        pub const SERVO_PREF_ENABLED_animation_iteration_count: bool = false;
+        pub const SERVO_PREF_ENABLED_animation_name: bool = false;
+        pub const SERVO_PREF_ENABLED_animation_play_state: bool = false;
+        pub const SERVO_PREF_ENABLED_animation_timing_function: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_appearance: bool = false;
+        pub const SERVO_PREF_ENABLED_backface_visibility: bool = false;
+        pub const SERVO_PREF_ENABLED_background: bool = false;
+        pub const SERVO_PREF_ENABLED_background_attachment: bool = false;
+        pub const SERVO_PREF_ENABLED_background_blend_mode: bool = true;
+        pub const SERVO_PREF_ENABLED_background_clip: bool = false;
+        pub const SERVO_PREF_ENABLED_background_color: bool = false;
+        pub const SERVO_PREF_ENABLED_background_image: bool = false;
+        pub const SERVO_PREF_ENABLED_background_origin: bool = false;
+        pub const SERVO_PREF_ENABLED_background_position: bool = false;
+        pub const SERVO_PREF_ENABLED_background_position_x: bool = false;
+        pub const SERVO_PREF_ENABLED_background_position_y: bool = false;
+        pub const SERVO_PREF_ENABLED_background_repeat: bool = false;
+        pub const SERVO_PREF_ENABLED_background_size: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_binding: bool = false;
+        pub const SERVO_PREF_ENABLED_block_size: bool = false;
+        pub const SERVO_PREF_ENABLED_border: bool = false;
+        pub const SERVO_PREF_ENABLED_border_block_end: bool = false;
+        pub const SERVO_PREF_ENABLED_border_block_end_color: bool = false;
+        pub const SERVO_PREF_ENABLED_border_block_end_style: bool = false;
+        pub const SERVO_PREF_ENABLED_border_block_end_width: bool = false;
+        pub const SERVO_PREF_ENABLED_border_block_start: bool = false;
+        pub const SERVO_PREF_ENABLED_border_block_start_color: bool = false;
+        pub const SERVO_PREF_ENABLED_border_block_start_style: bool = false;
+        pub const SERVO_PREF_ENABLED_border_block_start_width: bool = false;
+        pub const SERVO_PREF_ENABLED_border_bottom: bool = false;
+        pub const SERVO_PREF_ENABLED_border_bottom_color: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_border_bottom_colors: bool = false;
+        pub const SERVO_PREF_ENABLED_border_bottom_left_radius: bool = false;
+        pub const SERVO_PREF_ENABLED_border_bottom_right_radius: bool = false;
+        pub const SERVO_PREF_ENABLED_border_bottom_style: bool = false;
+        pub const SERVO_PREF_ENABLED_border_bottom_width: bool = false;
+        pub const SERVO_PREF_ENABLED_border_collapse: bool = false;
+        pub const SERVO_PREF_ENABLED_border_color: bool = false;
+        pub const SERVO_PREF_ENABLED_border_image: bool = false;
+        pub const SERVO_PREF_ENABLED_border_image_outset: bool = false;
+        pub const SERVO_PREF_ENABLED_border_image_repeat: bool = false;
+        pub const SERVO_PREF_ENABLED_border_image_slice: bool = false;
+        pub const SERVO_PREF_ENABLED_border_image_source: bool = false;
+        pub const SERVO_PREF_ENABLED_border_image_width: bool = false;
+        pub const SERVO_PREF_ENABLED_border_inline_end: bool = false;
+        pub const SERVO_PREF_ENABLED_border_inline_end_color: bool = false;
+        pub const SERVO_PREF_ENABLED_border_inline_end_style: bool = false;
+        pub const SERVO_PREF_ENABLED_border_inline_end_width: bool = false;
+        pub const SERVO_PREF_ENABLED_border_inline_start: bool = false;
+        pub const SERVO_PREF_ENABLED_border_inline_start_color: bool = false;
+        pub const SERVO_PREF_ENABLED_border_inline_start_style: bool = false;
+        pub const SERVO_PREF_ENABLED_border_inline_start_width: bool = false;
+        pub const SERVO_PREF_ENABLED_border_left: bool = false;
+        pub const SERVO_PREF_ENABLED_border_left_color: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_border_left_colors: bool = false;
+        pub const SERVO_PREF_ENABLED_border_left_style: bool = false;
+        pub const SERVO_PREF_ENABLED_border_left_width: bool = false;
+        pub const SERVO_PREF_ENABLED_border_radius: bool = false;
+        pub const SERVO_PREF_ENABLED_border_right: bool = false;
+        pub const SERVO_PREF_ENABLED_border_right_color: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_border_right_colors: bool = false;
+        pub const SERVO_PREF_ENABLED_border_right_style: bool = false;
+        pub const SERVO_PREF_ENABLED_border_right_width: bool = false;
+        pub const SERVO_PREF_ENABLED_border_spacing: bool = false;
+        pub const SERVO_PREF_ENABLED_border_style: bool = false;
+        pub const SERVO_PREF_ENABLED_border_top: bool = false;
+        pub const SERVO_PREF_ENABLED_border_top_color: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_border_top_colors: bool = false;
+        pub const SERVO_PREF_ENABLED_border_top_left_radius: bool = false;
+        pub const SERVO_PREF_ENABLED_border_top_right_radius: bool = false;
+        pub const SERVO_PREF_ENABLED_border_top_style: bool = false;
+        pub const SERVO_PREF_ENABLED_border_top_width: bool = false;
+        pub const SERVO_PREF_ENABLED_border_width: bool = false;
+        pub const SERVO_PREF_ENABLED_bottom: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_box_align: bool = false;
+        pub const SERVO_PREF_ENABLED_box_decoration_break: bool = true;
+        pub const SERVO_PREF_ENABLED__moz_box_direction: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_box_flex: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_box_ordinal_group: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_box_orient: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_box_pack: bool = false;
+        pub const SERVO_PREF_ENABLED_box_shadow: bool = false;
+        pub const SERVO_PREF_ENABLED_box_sizing: bool = false;
+        pub const SERVO_PREF_ENABLED_caption_side: bool = false;
+        pub const SERVO_PREF_ENABLED_caret_color: bool = false;
+        pub const SERVO_PREF_ENABLED_clear: bool = false;
+        pub const SERVO_PREF_ENABLED_clip: bool = false;
+        pub const SERVO_PREF_ENABLED_clip_path: bool = false;
+        pub const SERVO_PREF_ENABLED_clip_rule: bool = false;
+        pub const SERVO_PREF_ENABLED_color: bool = false;
+        pub const SERVO_PREF_ENABLED_color_adjust: bool = true;
+        pub const SERVO_PREF_ENABLED_color_interpolation: bool = false;
+        pub const SERVO_PREF_ENABLED_color_interpolation_filters: bool =
+            false;
+        pub const SERVO_PREF_ENABLED_column_count: bool = false;
+        pub const SERVO_PREF_ENABLED_column_fill: bool = false;
+        pub const SERVO_PREF_ENABLED_column_gap: bool = false;
+        pub const SERVO_PREF_ENABLED_column_rule: bool = false;
+        pub const SERVO_PREF_ENABLED_column_rule_color: bool = false;
+        pub const SERVO_PREF_ENABLED_column_rule_style: bool = false;
+        pub const SERVO_PREF_ENABLED_column_rule_width: bool = false;
+        pub const SERVO_PREF_ENABLED_column_width: bool = false;
+        pub const SERVO_PREF_ENABLED_columns: bool = false;
+        pub const SERVO_PREF_ENABLED_contain: bool = true;
+        pub const SERVO_PREF_ENABLED_content: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_control_character_visibility: bool =
+            false;
+        pub const SERVO_PREF_ENABLED_counter_increment: bool = false;
+        pub const SERVO_PREF_ENABLED_counter_reset: bool = false;
+        pub const SERVO_PREF_ENABLED_cursor: bool = false;
+        pub const SERVO_PREF_ENABLED_direction: bool = false;
+        pub const SERVO_PREF_ENABLED_display: bool = false;
+        pub const SERVO_PREF_ENABLED_dominant_baseline: bool = false;
+        pub const SERVO_PREF_ENABLED_empty_cells: bool = false;
+        pub const SERVO_PREF_ENABLED_fill: bool = false;
+        pub const SERVO_PREF_ENABLED_fill_opacity: bool = false;
+        pub const SERVO_PREF_ENABLED_fill_rule: bool = false;
+        pub const SERVO_PREF_ENABLED_filter: bool = false;
+        pub const SERVO_PREF_ENABLED_flex: bool = false;
+        pub const SERVO_PREF_ENABLED_flex_basis: bool = false;
+        pub const SERVO_PREF_ENABLED_flex_direction: bool = false;
+        pub const SERVO_PREF_ENABLED_flex_flow: bool = false;
+        pub const SERVO_PREF_ENABLED_flex_grow: bool = false;
+        pub const SERVO_PREF_ENABLED_flex_shrink: bool = false;
+        pub const SERVO_PREF_ENABLED_flex_wrap: bool = false;
+        pub const SERVO_PREF_ENABLED_float_: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_float_edge: bool = false;
+        pub const SERVO_PREF_ENABLED_flood_color: bool = false;
+        pub const SERVO_PREF_ENABLED_flood_opacity: bool = false;
+        pub const SERVO_PREF_ENABLED_font: bool = false;
+        pub const SERVO_PREF_ENABLED_font_family: bool = false;
+        pub const SERVO_PREF_ENABLED_font_feature_settings: bool = false;
+        pub const SERVO_PREF_ENABLED_font_kerning: bool = false;
+        pub const SERVO_PREF_ENABLED_font_language_override: bool = false;
+        pub const SERVO_PREF_ENABLED_font_size: bool = false;
+        pub const SERVO_PREF_ENABLED_font_size_adjust: bool = false;
+        pub const SERVO_PREF_ENABLED_font_stretch: bool = false;
+        pub const SERVO_PREF_ENABLED_font_style: bool = false;
+        pub const SERVO_PREF_ENABLED_font_synthesis: bool = false;
+        pub const SERVO_PREF_ENABLED_font_variant: bool = false;
+        pub const SERVO_PREF_ENABLED_font_variant_alternates: bool = false;
+        pub const SERVO_PREF_ENABLED_font_variant_caps: bool = false;
+        pub const SERVO_PREF_ENABLED_font_variant_east_asian: bool = false;
+        pub const SERVO_PREF_ENABLED_font_variant_ligatures: bool = false;
+        pub const SERVO_PREF_ENABLED_font_variant_numeric: bool = false;
+        pub const SERVO_PREF_ENABLED_font_variant_position: bool = false;
+        pub const SERVO_PREF_ENABLED_font_variation_settings: bool = true;
+        pub const SERVO_PREF_ENABLED_font_weight: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_force_broken_image_icon: bool =
+            false;
+        pub const SERVO_PREF_ENABLED_grid: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_area: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_auto_columns: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_auto_flow: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_auto_rows: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_column: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_column_end: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_column_gap: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_column_start: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_gap: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_row: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_row_end: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_row_gap: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_row_start: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_template: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_template_areas: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_template_columns: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_template_rows: bool = true;
+        pub const SERVO_PREF_ENABLED_height: bool = false;
+        pub const SERVO_PREF_ENABLED_hyphens: bool = false;
+        pub const SERVO_PREF_ENABLED_initial_letter: bool = true;
+        pub const SERVO_PREF_ENABLED_image_orientation: bool = true;
+        pub const SERVO_PREF_ENABLED__moz_image_region: bool = false;
+        pub const SERVO_PREF_ENABLED_image_rendering: bool = false;
+        pub const SERVO_PREF_ENABLED_ime_mode: bool = false;
+        pub const SERVO_PREF_ENABLED_inline_size: bool = false;
+        pub const SERVO_PREF_ENABLED_isolation: bool = true;
+        pub const SERVO_PREF_ENABLED_justify_content: bool = false;
+        pub const SERVO_PREF_ENABLED_justify_items: bool = false;
+        pub const SERVO_PREF_ENABLED_justify_self: bool = false;
+        pub const SERVO_PREF_ENABLED__x_lang: bool = false;
+        pub const SERVO_PREF_ENABLED_left: bool = false;
+        pub const SERVO_PREF_ENABLED_letter_spacing: bool = false;
+        pub const SERVO_PREF_ENABLED_lighting_color: bool = false;
+        pub const SERVO_PREF_ENABLED_line_height: bool = false;
+        pub const SERVO_PREF_ENABLED_list_style: bool = false;
+        pub const SERVO_PREF_ENABLED_list_style_image: bool = false;
+        pub const SERVO_PREF_ENABLED_list_style_position: bool = false;
+        pub const SERVO_PREF_ENABLED_list_style_type: bool = false;
+        pub const SERVO_PREF_ENABLED_margin: bool = false;
+        pub const SERVO_PREF_ENABLED_margin_block_end: bool = false;
+        pub const SERVO_PREF_ENABLED_margin_block_start: bool = false;
+        pub const SERVO_PREF_ENABLED_margin_bottom: bool = false;
+        pub const SERVO_PREF_ENABLED_margin_inline_end: bool = false;
+        pub const SERVO_PREF_ENABLED_margin_inline_start: bool = false;
+        pub const SERVO_PREF_ENABLED_margin_left: bool = false;
+        pub const SERVO_PREF_ENABLED_margin_right: bool = false;
+        pub const SERVO_PREF_ENABLED_margin_top: bool = false;
+        pub const SERVO_PREF_ENABLED_marker: bool = false;
+        pub const SERVO_PREF_ENABLED_marker_end: bool = false;
+        pub const SERVO_PREF_ENABLED_marker_mid: bool = false;
+        pub const SERVO_PREF_ENABLED_marker_start: bool = false;
+        pub const SERVO_PREF_ENABLED_mask: bool = false;
+        pub const SERVO_PREF_ENABLED_mask_clip: bool = false;
+        pub const SERVO_PREF_ENABLED_mask_composite: bool = false;
+        pub const SERVO_PREF_ENABLED_mask_image: bool = false;
+        pub const SERVO_PREF_ENABLED_mask_mode: bool = false;
+        pub const SERVO_PREF_ENABLED_mask_origin: bool = false;
+        pub const SERVO_PREF_ENABLED_mask_position: bool = false;
+        pub const SERVO_PREF_ENABLED_mask_position_x: bool = false;
+        pub const SERVO_PREF_ENABLED_mask_position_y: bool = false;
+        pub const SERVO_PREF_ENABLED_mask_repeat: bool = false;
+        pub const SERVO_PREF_ENABLED_mask_size: bool = false;
+        pub const SERVO_PREF_ENABLED_mask_type: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_math_display: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_math_variant: bool = false;
+        pub const SERVO_PREF_ENABLED_max_block_size: bool = false;
+        pub const SERVO_PREF_ENABLED_max_height: bool = false;
+        pub const SERVO_PREF_ENABLED_max_inline_size: bool = false;
+        pub const SERVO_PREF_ENABLED_max_width: bool = false;
+        pub const SERVO_PREF_ENABLED_min_block_size: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_min_font_size_ratio: bool = false;
+        pub const SERVO_PREF_ENABLED_min_height: bool = false;
+        pub const SERVO_PREF_ENABLED_min_inline_size: bool = false;
+        pub const SERVO_PREF_ENABLED_min_width: bool = false;
+        pub const SERVO_PREF_ENABLED_mix_blend_mode: bool = true;
+        pub const SERVO_PREF_ENABLED_object_fit: bool = true;
+        pub const SERVO_PREF_ENABLED_object_position: bool = true;
+        pub const SERVO_PREF_ENABLED_offset_block_end: bool = false;
+        pub const SERVO_PREF_ENABLED_offset_block_start: bool = false;
+        pub const SERVO_PREF_ENABLED_offset_inline_end: bool = false;
+        pub const SERVO_PREF_ENABLED_offset_inline_start: bool = false;
+        pub const SERVO_PREF_ENABLED_opacity: bool = false;
+        pub const SERVO_PREF_ENABLED_order: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_orient: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_osx_font_smoothing: bool = true;
+        pub const SERVO_PREF_ENABLED_outline: bool = false;
+        pub const SERVO_PREF_ENABLED_outline_color: bool = false;
+        pub const SERVO_PREF_ENABLED_outline_offset: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_outline_radius: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_outline_radius_bottomleft: bool =
+            false;
+        pub const SERVO_PREF_ENABLED__moz_outline_radius_bottomright: bool =
+            false;
+        pub const SERVO_PREF_ENABLED__moz_outline_radius_topleft: bool =
+            false;
+        pub const SERVO_PREF_ENABLED__moz_outline_radius_topright: bool =
+            false;
+        pub const SERVO_PREF_ENABLED_outline_style: bool = false;
+        pub const SERVO_PREF_ENABLED_outline_width: bool = false;
+        pub const SERVO_PREF_ENABLED_overflow: bool = false;
+        pub const SERVO_PREF_ENABLED_overflow_clip_box: bool = true;
+        pub const SERVO_PREF_ENABLED_overflow_x: bool = false;
+        pub const SERVO_PREF_ENABLED_overflow_y: bool = false;
+        pub const SERVO_PREF_ENABLED_padding: bool = false;
+        pub const SERVO_PREF_ENABLED_padding_block_end: bool = false;
+        pub const SERVO_PREF_ENABLED_padding_block_start: bool = false;
+        pub const SERVO_PREF_ENABLED_padding_bottom: bool = false;
+        pub const SERVO_PREF_ENABLED_padding_inline_end: bool = false;
+        pub const SERVO_PREF_ENABLED_padding_inline_start: bool = false;
+        pub const SERVO_PREF_ENABLED_padding_left: bool = false;
+        pub const SERVO_PREF_ENABLED_padding_right: bool = false;
+        pub const SERVO_PREF_ENABLED_padding_top: bool = false;
+        pub const SERVO_PREF_ENABLED_page_break_after: bool = false;
+        pub const SERVO_PREF_ENABLED_page_break_before: bool = false;
+        pub const SERVO_PREF_ENABLED_page_break_inside: bool = false;
+        pub const SERVO_PREF_ENABLED_paint_order: bool = true;
+        pub const SERVO_PREF_ENABLED_perspective: bool = false;
+        pub const SERVO_PREF_ENABLED_perspective_origin: bool = false;
+        pub const SERVO_PREF_ENABLED_place_content: bool = false;
+        pub const SERVO_PREF_ENABLED_place_items: bool = false;
+        pub const SERVO_PREF_ENABLED_place_self: bool = false;
+        pub const SERVO_PREF_ENABLED_pointer_events: bool = false;
+        pub const SERVO_PREF_ENABLED_position: bool = false;
+        pub const SERVO_PREF_ENABLED_quotes: bool = false;
+        pub const SERVO_PREF_ENABLED_resize: bool = false;
+        pub const SERVO_PREF_ENABLED_right: bool = false;
+        pub const SERVO_PREF_ENABLED_ruby_align: bool = false;
+        pub const SERVO_PREF_ENABLED_ruby_position: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_script_level: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_script_min_size: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_script_size_multiplier: bool =
+            false;
+        pub const SERVO_PREF_ENABLED_scroll_behavior: bool = true;
+        pub const SERVO_PREF_ENABLED_scroll_snap_coordinate: bool = true;
+        pub const SERVO_PREF_ENABLED_scroll_snap_destination: bool = true;
+        pub const SERVO_PREF_ENABLED_scroll_snap_points_x: bool = true;
+        pub const SERVO_PREF_ENABLED_scroll_snap_points_y: bool = true;
+        pub const SERVO_PREF_ENABLED_scroll_snap_type: bool = true;
+        pub const SERVO_PREF_ENABLED_scroll_snap_type_x: bool = true;
+        pub const SERVO_PREF_ENABLED_scroll_snap_type_y: bool = true;
+        pub const SERVO_PREF_ENABLED_shape_outside: bool = true;
+        pub const SERVO_PREF_ENABLED_shape_rendering: bool = false;
+        pub const SERVO_PREF_ENABLED__x_span: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_stack_sizing: bool = false;
+        pub const SERVO_PREF_ENABLED_stop_color: bool = false;
+        pub const SERVO_PREF_ENABLED_stop_opacity: bool = false;
+        pub const SERVO_PREF_ENABLED_stroke: bool = false;
+        pub const SERVO_PREF_ENABLED_stroke_dasharray: bool = false;
+        pub const SERVO_PREF_ENABLED_stroke_dashoffset: bool = false;
+        pub const SERVO_PREF_ENABLED_stroke_linecap: bool = false;
+        pub const SERVO_PREF_ENABLED_stroke_linejoin: bool = false;
+        pub const SERVO_PREF_ENABLED_stroke_miterlimit: bool = false;
+        pub const SERVO_PREF_ENABLED_stroke_opacity: bool = false;
+        pub const SERVO_PREF_ENABLED_stroke_width: bool = false;
+        pub const SERVO_PREF_ENABLED__x_system_font: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_tab_size: bool = false;
+        pub const SERVO_PREF_ENABLED_table_layout: bool = false;
+        pub const SERVO_PREF_ENABLED_text_align: bool = false;
+        pub const SERVO_PREF_ENABLED_text_align_last: bool = false;
+        pub const SERVO_PREF_ENABLED_text_anchor: bool = false;
+        pub const SERVO_PREF_ENABLED_text_combine_upright: bool = true;
+        pub const SERVO_PREF_ENABLED_text_decoration: bool = false;
+        pub const SERVO_PREF_ENABLED_text_decoration_color: bool = false;
+        pub const SERVO_PREF_ENABLED_text_decoration_line: bool = false;
+        pub const SERVO_PREF_ENABLED_text_decoration_style: bool = false;
+        pub const SERVO_PREF_ENABLED_text_emphasis: bool = false;
+        pub const SERVO_PREF_ENABLED_text_emphasis_color: bool = false;
+        pub const SERVO_PREF_ENABLED_text_emphasis_position: bool = false;
+        pub const SERVO_PREF_ENABLED_text_emphasis_style: bool = false;
+        pub const SERVO_PREF_ENABLED__webkit_text_fill_color: bool = true;
+        pub const SERVO_PREF_ENABLED_text_indent: bool = false;
+        pub const SERVO_PREF_ENABLED_text_orientation: bool = false;
+        pub const SERVO_PREF_ENABLED_text_overflow: bool = false;
+        pub const SERVO_PREF_ENABLED_text_rendering: bool = false;
+        pub const SERVO_PREF_ENABLED_text_shadow: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_text_size_adjust: bool = false;
+        pub const SERVO_PREF_ENABLED__webkit_text_stroke: bool = true;
+        pub const SERVO_PREF_ENABLED__webkit_text_stroke_color: bool = true;
+        pub const SERVO_PREF_ENABLED__webkit_text_stroke_width: bool = true;
+        pub const SERVO_PREF_ENABLED_text_transform: bool = false;
+        pub const SERVO_PREF_ENABLED__x_text_zoom: bool = false;
+        pub const SERVO_PREF_ENABLED_top: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_top_layer: bool = false;
+        pub const SERVO_PREF_ENABLED_touch_action: bool = true;
+        pub const SERVO_PREF_ENABLED_transform: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_transform: bool = true;
+        pub const SERVO_PREF_ENABLED_transform_box: bool = true;
+        pub const SERVO_PREF_ENABLED_transform_origin: bool = false;
+        pub const SERVO_PREF_ENABLED_transform_style: bool = false;
+        pub const SERVO_PREF_ENABLED_transition: bool = false;
+        pub const SERVO_PREF_ENABLED_transition_delay: bool = false;
+        pub const SERVO_PREF_ENABLED_transition_duration: bool = false;
+        pub const SERVO_PREF_ENABLED_transition_property: bool = false;
+        pub const SERVO_PREF_ENABLED_transition_timing_function: bool = false;
+        pub const SERVO_PREF_ENABLED_unicode_bidi: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_user_focus: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_user_input: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_user_modify: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_user_select: bool = false;
+        pub const SERVO_PREF_ENABLED_vector_effect: bool = false;
+        pub const SERVO_PREF_ENABLED_vertical_align: bool = false;
+        pub const SERVO_PREF_ENABLED_visibility: bool = false;
+        pub const SERVO_PREF_ENABLED_white_space: bool = false;
+        pub const SERVO_PREF_ENABLED_width: bool = false;
+        pub const SERVO_PREF_ENABLED_will_change: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_window_dragging: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_window_shadow: bool = false;
+        pub const SERVO_PREF_ENABLED_word_break: bool = false;
+        pub const SERVO_PREF_ENABLED_word_spacing: bool = false;
+        pub const SERVO_PREF_ENABLED_overflow_wrap: bool = false;
+        pub const SERVO_PREF_ENABLED_writing_mode: bool = false;
+        pub const SERVO_PREF_ENABLED_z_index: bool = false;
         #[repr(C)]
         #[derive(Debug, Copy)]
         pub struct fallible_t {
diff --git a/components/style/gecko_bindings/structs_release.rs b/components/style/gecko_bindings/structs_release.rs
index 95030a8f8dd..2d7be3d7210 100644
--- a/components/style/gecko_bindings/structs_release.rs
+++ b/components/style/gecko_bindings/structs_release.rs
@@ -1048,6 +1048,378 @@ pub mod root {
     pub mod mozilla {
         #[allow(unused_imports)]
         use self::super::super::root;
+        pub const SERVO_PREF_ENABLED_align_content: bool = false;
+        pub const SERVO_PREF_ENABLED_align_items: bool = false;
+        pub const SERVO_PREF_ENABLED_align_self: bool = false;
+        pub const SERVO_PREF_ENABLED_all: bool = true;
+        pub const SERVO_PREF_ENABLED_animation: bool = false;
+        pub const SERVO_PREF_ENABLED_animation_delay: bool = false;
+        pub const SERVO_PREF_ENABLED_animation_direction: bool = false;
+        pub const SERVO_PREF_ENABLED_animation_duration: bool = false;
+        pub const SERVO_PREF_ENABLED_animation_fill_mode: bool = false;
+        pub const SERVO_PREF_ENABLED_animation_iteration_count: bool = false;
+        pub const SERVO_PREF_ENABLED_animation_name: bool = false;
+        pub const SERVO_PREF_ENABLED_animation_play_state: bool = false;
+        pub const SERVO_PREF_ENABLED_animation_timing_function: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_appearance: bool = false;
+        pub const SERVO_PREF_ENABLED_backface_visibility: bool = false;
+        pub const SERVO_PREF_ENABLED_background: bool = false;
+        pub const SERVO_PREF_ENABLED_background_attachment: bool = false;
+        pub const SERVO_PREF_ENABLED_background_blend_mode: bool = true;
+        pub const SERVO_PREF_ENABLED_background_clip: bool = false;
+        pub const SERVO_PREF_ENABLED_background_color: bool = false;
+        pub const SERVO_PREF_ENABLED_background_image: bool = false;
+        pub const SERVO_PREF_ENABLED_background_origin: bool = false;
+        pub const SERVO_PREF_ENABLED_background_position: bool = false;
+        pub const SERVO_PREF_ENABLED_background_position_x: bool = false;
+        pub const SERVO_PREF_ENABLED_background_position_y: bool = false;
+        pub const SERVO_PREF_ENABLED_background_repeat: bool = false;
+        pub const SERVO_PREF_ENABLED_background_size: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_binding: bool = false;
+        pub const SERVO_PREF_ENABLED_block_size: bool = false;
+        pub const SERVO_PREF_ENABLED_border: bool = false;
+        pub const SERVO_PREF_ENABLED_border_block_end: bool = false;
+        pub const SERVO_PREF_ENABLED_border_block_end_color: bool = false;
+        pub const SERVO_PREF_ENABLED_border_block_end_style: bool = false;
+        pub const SERVO_PREF_ENABLED_border_block_end_width: bool = false;
+        pub const SERVO_PREF_ENABLED_border_block_start: bool = false;
+        pub const SERVO_PREF_ENABLED_border_block_start_color: bool = false;
+        pub const SERVO_PREF_ENABLED_border_block_start_style: bool = false;
+        pub const SERVO_PREF_ENABLED_border_block_start_width: bool = false;
+        pub const SERVO_PREF_ENABLED_border_bottom: bool = false;
+        pub const SERVO_PREF_ENABLED_border_bottom_color: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_border_bottom_colors: bool = false;
+        pub const SERVO_PREF_ENABLED_border_bottom_left_radius: bool = false;
+        pub const SERVO_PREF_ENABLED_border_bottom_right_radius: bool = false;
+        pub const SERVO_PREF_ENABLED_border_bottom_style: bool = false;
+        pub const SERVO_PREF_ENABLED_border_bottom_width: bool = false;
+        pub const SERVO_PREF_ENABLED_border_collapse: bool = false;
+        pub const SERVO_PREF_ENABLED_border_color: bool = false;
+        pub const SERVO_PREF_ENABLED_border_image: bool = false;
+        pub const SERVO_PREF_ENABLED_border_image_outset: bool = false;
+        pub const SERVO_PREF_ENABLED_border_image_repeat: bool = false;
+        pub const SERVO_PREF_ENABLED_border_image_slice: bool = false;
+        pub const SERVO_PREF_ENABLED_border_image_source: bool = false;
+        pub const SERVO_PREF_ENABLED_border_image_width: bool = false;
+        pub const SERVO_PREF_ENABLED_border_inline_end: bool = false;
+        pub const SERVO_PREF_ENABLED_border_inline_end_color: bool = false;
+        pub const SERVO_PREF_ENABLED_border_inline_end_style: bool = false;
+        pub const SERVO_PREF_ENABLED_border_inline_end_width: bool = false;
+        pub const SERVO_PREF_ENABLED_border_inline_start: bool = false;
+        pub const SERVO_PREF_ENABLED_border_inline_start_color: bool = false;
+        pub const SERVO_PREF_ENABLED_border_inline_start_style: bool = false;
+        pub const SERVO_PREF_ENABLED_border_inline_start_width: bool = false;
+        pub const SERVO_PREF_ENABLED_border_left: bool = false;
+        pub const SERVO_PREF_ENABLED_border_left_color: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_border_left_colors: bool = false;
+        pub const SERVO_PREF_ENABLED_border_left_style: bool = false;
+        pub const SERVO_PREF_ENABLED_border_left_width: bool = false;
+        pub const SERVO_PREF_ENABLED_border_radius: bool = false;
+        pub const SERVO_PREF_ENABLED_border_right: bool = false;
+        pub const SERVO_PREF_ENABLED_border_right_color: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_border_right_colors: bool = false;
+        pub const SERVO_PREF_ENABLED_border_right_style: bool = false;
+        pub const SERVO_PREF_ENABLED_border_right_width: bool = false;
+        pub const SERVO_PREF_ENABLED_border_spacing: bool = false;
+        pub const SERVO_PREF_ENABLED_border_style: bool = false;
+        pub const SERVO_PREF_ENABLED_border_top: bool = false;
+        pub const SERVO_PREF_ENABLED_border_top_color: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_border_top_colors: bool = false;
+        pub const SERVO_PREF_ENABLED_border_top_left_radius: bool = false;
+        pub const SERVO_PREF_ENABLED_border_top_right_radius: bool = false;
+        pub const SERVO_PREF_ENABLED_border_top_style: bool = false;
+        pub const SERVO_PREF_ENABLED_border_top_width: bool = false;
+        pub const SERVO_PREF_ENABLED_border_width: bool = false;
+        pub const SERVO_PREF_ENABLED_bottom: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_box_align: bool = false;
+        pub const SERVO_PREF_ENABLED_box_decoration_break: bool = true;
+        pub const SERVO_PREF_ENABLED__moz_box_direction: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_box_flex: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_box_ordinal_group: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_box_orient: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_box_pack: bool = false;
+        pub const SERVO_PREF_ENABLED_box_shadow: bool = false;
+        pub const SERVO_PREF_ENABLED_box_sizing: bool = false;
+        pub const SERVO_PREF_ENABLED_caption_side: bool = false;
+        pub const SERVO_PREF_ENABLED_caret_color: bool = false;
+        pub const SERVO_PREF_ENABLED_clear: bool = false;
+        pub const SERVO_PREF_ENABLED_clip: bool = false;
+        pub const SERVO_PREF_ENABLED_clip_path: bool = false;
+        pub const SERVO_PREF_ENABLED_clip_rule: bool = false;
+        pub const SERVO_PREF_ENABLED_color: bool = false;
+        pub const SERVO_PREF_ENABLED_color_adjust: bool = true;
+        pub const SERVO_PREF_ENABLED_color_interpolation: bool = false;
+        pub const SERVO_PREF_ENABLED_color_interpolation_filters: bool =
+            false;
+        pub const SERVO_PREF_ENABLED_column_count: bool = false;
+        pub const SERVO_PREF_ENABLED_column_fill: bool = false;
+        pub const SERVO_PREF_ENABLED_column_gap: bool = false;
+        pub const SERVO_PREF_ENABLED_column_rule: bool = false;
+        pub const SERVO_PREF_ENABLED_column_rule_color: bool = false;
+        pub const SERVO_PREF_ENABLED_column_rule_style: bool = false;
+        pub const SERVO_PREF_ENABLED_column_rule_width: bool = false;
+        pub const SERVO_PREF_ENABLED_column_width: bool = false;
+        pub const SERVO_PREF_ENABLED_columns: bool = false;
+        pub const SERVO_PREF_ENABLED_contain: bool = true;
+        pub const SERVO_PREF_ENABLED_content: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_control_character_visibility: bool =
+            false;
+        pub const SERVO_PREF_ENABLED_counter_increment: bool = false;
+        pub const SERVO_PREF_ENABLED_counter_reset: bool = false;
+        pub const SERVO_PREF_ENABLED_cursor: bool = false;
+        pub const SERVO_PREF_ENABLED_direction: bool = false;
+        pub const SERVO_PREF_ENABLED_display: bool = false;
+        pub const SERVO_PREF_ENABLED_dominant_baseline: bool = false;
+        pub const SERVO_PREF_ENABLED_empty_cells: bool = false;
+        pub const SERVO_PREF_ENABLED_fill: bool = false;
+        pub const SERVO_PREF_ENABLED_fill_opacity: bool = false;
+        pub const SERVO_PREF_ENABLED_fill_rule: bool = false;
+        pub const SERVO_PREF_ENABLED_filter: bool = false;
+        pub const SERVO_PREF_ENABLED_flex: bool = false;
+        pub const SERVO_PREF_ENABLED_flex_basis: bool = false;
+        pub const SERVO_PREF_ENABLED_flex_direction: bool = false;
+        pub const SERVO_PREF_ENABLED_flex_flow: bool = false;
+        pub const SERVO_PREF_ENABLED_flex_grow: bool = false;
+        pub const SERVO_PREF_ENABLED_flex_shrink: bool = false;
+        pub const SERVO_PREF_ENABLED_flex_wrap: bool = false;
+        pub const SERVO_PREF_ENABLED_float_: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_float_edge: bool = false;
+        pub const SERVO_PREF_ENABLED_flood_color: bool = false;
+        pub const SERVO_PREF_ENABLED_flood_opacity: bool = false;
+        pub const SERVO_PREF_ENABLED_font: bool = false;
+        pub const SERVO_PREF_ENABLED_font_family: bool = false;
+        pub const SERVO_PREF_ENABLED_font_feature_settings: bool = false;
+        pub const SERVO_PREF_ENABLED_font_kerning: bool = false;
+        pub const SERVO_PREF_ENABLED_font_language_override: bool = false;
+        pub const SERVO_PREF_ENABLED_font_size: bool = false;
+        pub const SERVO_PREF_ENABLED_font_size_adjust: bool = false;
+        pub const SERVO_PREF_ENABLED_font_stretch: bool = false;
+        pub const SERVO_PREF_ENABLED_font_style: bool = false;
+        pub const SERVO_PREF_ENABLED_font_synthesis: bool = false;
+        pub const SERVO_PREF_ENABLED_font_variant: bool = false;
+        pub const SERVO_PREF_ENABLED_font_variant_alternates: bool = false;
+        pub const SERVO_PREF_ENABLED_font_variant_caps: bool = false;
+        pub const SERVO_PREF_ENABLED_font_variant_east_asian: bool = false;
+        pub const SERVO_PREF_ENABLED_font_variant_ligatures: bool = false;
+        pub const SERVO_PREF_ENABLED_font_variant_numeric: bool = false;
+        pub const SERVO_PREF_ENABLED_font_variant_position: bool = false;
+        pub const SERVO_PREF_ENABLED_font_variation_settings: bool = true;
+        pub const SERVO_PREF_ENABLED_font_weight: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_force_broken_image_icon: bool =
+            false;
+        pub const SERVO_PREF_ENABLED_grid: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_area: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_auto_columns: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_auto_flow: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_auto_rows: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_column: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_column_end: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_column_gap: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_column_start: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_gap: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_row: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_row_end: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_row_gap: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_row_start: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_template: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_template_areas: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_template_columns: bool = true;
+        pub const SERVO_PREF_ENABLED_grid_template_rows: bool = true;
+        pub const SERVO_PREF_ENABLED_height: bool = false;
+        pub const SERVO_PREF_ENABLED_hyphens: bool = false;
+        pub const SERVO_PREF_ENABLED_initial_letter: bool = true;
+        pub const SERVO_PREF_ENABLED_image_orientation: bool = true;
+        pub const SERVO_PREF_ENABLED__moz_image_region: bool = false;
+        pub const SERVO_PREF_ENABLED_image_rendering: bool = false;
+        pub const SERVO_PREF_ENABLED_ime_mode: bool = false;
+        pub const SERVO_PREF_ENABLED_inline_size: bool = false;
+        pub const SERVO_PREF_ENABLED_isolation: bool = true;
+        pub const SERVO_PREF_ENABLED_justify_content: bool = false;
+        pub const SERVO_PREF_ENABLED_justify_items: bool = false;
+        pub const SERVO_PREF_ENABLED_justify_self: bool = false;
+        pub const SERVO_PREF_ENABLED__x_lang: bool = false;
+        pub const SERVO_PREF_ENABLED_left: bool = false;
+        pub const SERVO_PREF_ENABLED_letter_spacing: bool = false;
+        pub const SERVO_PREF_ENABLED_lighting_color: bool = false;
+        pub const SERVO_PREF_ENABLED_line_height: bool = false;
+        pub const SERVO_PREF_ENABLED_list_style: bool = false;
+        pub const SERVO_PREF_ENABLED_list_style_image: bool = false;
+        pub const SERVO_PREF_ENABLED_list_style_position: bool = false;
+        pub const SERVO_PREF_ENABLED_list_style_type: bool = false;
+        pub const SERVO_PREF_ENABLED_margin: bool = false;
+        pub const SERVO_PREF_ENABLED_margin_block_end: bool = false;
+        pub const SERVO_PREF_ENABLED_margin_block_start: bool = false;
+        pub const SERVO_PREF_ENABLED_margin_bottom: bool = false;
+        pub const SERVO_PREF_ENABLED_margin_inline_end: bool = false;
+        pub const SERVO_PREF_ENABLED_margin_inline_start: bool = false;
+        pub const SERVO_PREF_ENABLED_margin_left: bool = false;
+        pub const SERVO_PREF_ENABLED_margin_right: bool = false;
+        pub const SERVO_PREF_ENABLED_margin_top: bool = false;
+        pub const SERVO_PREF_ENABLED_marker: bool = false;
+        pub const SERVO_PREF_ENABLED_marker_end: bool = false;
+        pub const SERVO_PREF_ENABLED_marker_mid: bool = false;
+        pub const SERVO_PREF_ENABLED_marker_start: bool = false;
+        pub const SERVO_PREF_ENABLED_mask: bool = false;
+        pub const SERVO_PREF_ENABLED_mask_clip: bool = false;
+        pub const SERVO_PREF_ENABLED_mask_composite: bool = false;
+        pub const SERVO_PREF_ENABLED_mask_image: bool = false;
+        pub const SERVO_PREF_ENABLED_mask_mode: bool = false;
+        pub const SERVO_PREF_ENABLED_mask_origin: bool = false;
+        pub const SERVO_PREF_ENABLED_mask_position: bool = false;
+        pub const SERVO_PREF_ENABLED_mask_position_x: bool = false;
+        pub const SERVO_PREF_ENABLED_mask_position_y: bool = false;
+        pub const SERVO_PREF_ENABLED_mask_repeat: bool = false;
+        pub const SERVO_PREF_ENABLED_mask_size: bool = false;
+        pub const SERVO_PREF_ENABLED_mask_type: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_math_display: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_math_variant: bool = false;
+        pub const SERVO_PREF_ENABLED_max_block_size: bool = false;
+        pub const SERVO_PREF_ENABLED_max_height: bool = false;
+        pub const SERVO_PREF_ENABLED_max_inline_size: bool = false;
+        pub const SERVO_PREF_ENABLED_max_width: bool = false;
+        pub const SERVO_PREF_ENABLED_min_block_size: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_min_font_size_ratio: bool = false;
+        pub const SERVO_PREF_ENABLED_min_height: bool = false;
+        pub const SERVO_PREF_ENABLED_min_inline_size: bool = false;
+        pub const SERVO_PREF_ENABLED_min_width: bool = false;
+        pub const SERVO_PREF_ENABLED_mix_blend_mode: bool = true;
+        pub const SERVO_PREF_ENABLED_object_fit: bool = true;
+        pub const SERVO_PREF_ENABLED_object_position: bool = true;
+        pub const SERVO_PREF_ENABLED_offset_block_end: bool = false;
+        pub const SERVO_PREF_ENABLED_offset_block_start: bool = false;
+        pub const SERVO_PREF_ENABLED_offset_inline_end: bool = false;
+        pub const SERVO_PREF_ENABLED_offset_inline_start: bool = false;
+        pub const SERVO_PREF_ENABLED_opacity: bool = false;
+        pub const SERVO_PREF_ENABLED_order: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_orient: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_osx_font_smoothing: bool = true;
+        pub const SERVO_PREF_ENABLED_outline: bool = false;
+        pub const SERVO_PREF_ENABLED_outline_color: bool = false;
+        pub const SERVO_PREF_ENABLED_outline_offset: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_outline_radius: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_outline_radius_bottomleft: bool =
+            false;
+        pub const SERVO_PREF_ENABLED__moz_outline_radius_bottomright: bool =
+            false;
+        pub const SERVO_PREF_ENABLED__moz_outline_radius_topleft: bool =
+            false;
+        pub const SERVO_PREF_ENABLED__moz_outline_radius_topright: bool =
+            false;
+        pub const SERVO_PREF_ENABLED_outline_style: bool = false;
+        pub const SERVO_PREF_ENABLED_outline_width: bool = false;
+        pub const SERVO_PREF_ENABLED_overflow: bool = false;
+        pub const SERVO_PREF_ENABLED_overflow_clip_box: bool = true;
+        pub const SERVO_PREF_ENABLED_overflow_x: bool = false;
+        pub const SERVO_PREF_ENABLED_overflow_y: bool = false;
+        pub const SERVO_PREF_ENABLED_padding: bool = false;
+        pub const SERVO_PREF_ENABLED_padding_block_end: bool = false;
+        pub const SERVO_PREF_ENABLED_padding_block_start: bool = false;
+        pub const SERVO_PREF_ENABLED_padding_bottom: bool = false;
+        pub const SERVO_PREF_ENABLED_padding_inline_end: bool = false;
+        pub const SERVO_PREF_ENABLED_padding_inline_start: bool = false;
+        pub const SERVO_PREF_ENABLED_padding_left: bool = false;
+        pub const SERVO_PREF_ENABLED_padding_right: bool = false;
+        pub const SERVO_PREF_ENABLED_padding_top: bool = false;
+        pub const SERVO_PREF_ENABLED_page_break_after: bool = false;
+        pub const SERVO_PREF_ENABLED_page_break_before: bool = false;
+        pub const SERVO_PREF_ENABLED_page_break_inside: bool = false;
+        pub const SERVO_PREF_ENABLED_paint_order: bool = true;
+        pub const SERVO_PREF_ENABLED_perspective: bool = false;
+        pub const SERVO_PREF_ENABLED_perspective_origin: bool = false;
+        pub const SERVO_PREF_ENABLED_place_content: bool = false;
+        pub const SERVO_PREF_ENABLED_place_items: bool = false;
+        pub const SERVO_PREF_ENABLED_place_self: bool = false;
+        pub const SERVO_PREF_ENABLED_pointer_events: bool = false;
+        pub const SERVO_PREF_ENABLED_position: bool = false;
+        pub const SERVO_PREF_ENABLED_quotes: bool = false;
+        pub const SERVO_PREF_ENABLED_resize: bool = false;
+        pub const SERVO_PREF_ENABLED_right: bool = false;
+        pub const SERVO_PREF_ENABLED_ruby_align: bool = false;
+        pub const SERVO_PREF_ENABLED_ruby_position: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_script_level: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_script_min_size: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_script_size_multiplier: bool =
+            false;
+        pub const SERVO_PREF_ENABLED_scroll_behavior: bool = true;
+        pub const SERVO_PREF_ENABLED_scroll_snap_coordinate: bool = true;
+        pub const SERVO_PREF_ENABLED_scroll_snap_destination: bool = true;
+        pub const SERVO_PREF_ENABLED_scroll_snap_points_x: bool = true;
+        pub const SERVO_PREF_ENABLED_scroll_snap_points_y: bool = true;
+        pub const SERVO_PREF_ENABLED_scroll_snap_type: bool = true;
+        pub const SERVO_PREF_ENABLED_scroll_snap_type_x: bool = true;
+        pub const SERVO_PREF_ENABLED_scroll_snap_type_y: bool = true;
+        pub const SERVO_PREF_ENABLED_shape_outside: bool = true;
+        pub const SERVO_PREF_ENABLED_shape_rendering: bool = false;
+        pub const SERVO_PREF_ENABLED__x_span: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_stack_sizing: bool = false;
+        pub const SERVO_PREF_ENABLED_stop_color: bool = false;
+        pub const SERVO_PREF_ENABLED_stop_opacity: bool = false;
+        pub const SERVO_PREF_ENABLED_stroke: bool = false;
+        pub const SERVO_PREF_ENABLED_stroke_dasharray: bool = false;
+        pub const SERVO_PREF_ENABLED_stroke_dashoffset: bool = false;
+        pub const SERVO_PREF_ENABLED_stroke_linecap: bool = false;
+        pub const SERVO_PREF_ENABLED_stroke_linejoin: bool = false;
+        pub const SERVO_PREF_ENABLED_stroke_miterlimit: bool = false;
+        pub const SERVO_PREF_ENABLED_stroke_opacity: bool = false;
+        pub const SERVO_PREF_ENABLED_stroke_width: bool = false;
+        pub const SERVO_PREF_ENABLED__x_system_font: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_tab_size: bool = false;
+        pub const SERVO_PREF_ENABLED_table_layout: bool = false;
+        pub const SERVO_PREF_ENABLED_text_align: bool = false;
+        pub const SERVO_PREF_ENABLED_text_align_last: bool = false;
+        pub const SERVO_PREF_ENABLED_text_anchor: bool = false;
+        pub const SERVO_PREF_ENABLED_text_combine_upright: bool = true;
+        pub const SERVO_PREF_ENABLED_text_decoration: bool = false;
+        pub const SERVO_PREF_ENABLED_text_decoration_color: bool = false;
+        pub const SERVO_PREF_ENABLED_text_decoration_line: bool = false;
+        pub const SERVO_PREF_ENABLED_text_decoration_style: bool = false;
+        pub const SERVO_PREF_ENABLED_text_emphasis: bool = false;
+        pub const SERVO_PREF_ENABLED_text_emphasis_color: bool = false;
+        pub const SERVO_PREF_ENABLED_text_emphasis_position: bool = false;
+        pub const SERVO_PREF_ENABLED_text_emphasis_style: bool = false;
+        pub const SERVO_PREF_ENABLED__webkit_text_fill_color: bool = true;
+        pub const SERVO_PREF_ENABLED_text_indent: bool = false;
+        pub const SERVO_PREF_ENABLED_text_orientation: bool = false;
+        pub const SERVO_PREF_ENABLED_text_overflow: bool = false;
+        pub const SERVO_PREF_ENABLED_text_rendering: bool = false;
+        pub const SERVO_PREF_ENABLED_text_shadow: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_text_size_adjust: bool = false;
+        pub const SERVO_PREF_ENABLED__webkit_text_stroke: bool = true;
+        pub const SERVO_PREF_ENABLED__webkit_text_stroke_color: bool = true;
+        pub const SERVO_PREF_ENABLED__webkit_text_stroke_width: bool = true;
+        pub const SERVO_PREF_ENABLED_text_transform: bool = false;
+        pub const SERVO_PREF_ENABLED__x_text_zoom: bool = false;
+        pub const SERVO_PREF_ENABLED_top: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_top_layer: bool = false;
+        pub const SERVO_PREF_ENABLED_touch_action: bool = true;
+        pub const SERVO_PREF_ENABLED_transform: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_transform: bool = true;
+        pub const SERVO_PREF_ENABLED_transform_box: bool = true;
+        pub const SERVO_PREF_ENABLED_transform_origin: bool = false;
+        pub const SERVO_PREF_ENABLED_transform_style: bool = false;
+        pub const SERVO_PREF_ENABLED_transition: bool = false;
+        pub const SERVO_PREF_ENABLED_transition_delay: bool = false;
+        pub const SERVO_PREF_ENABLED_transition_duration: bool = false;
+        pub const SERVO_PREF_ENABLED_transition_property: bool = false;
+        pub const SERVO_PREF_ENABLED_transition_timing_function: bool = false;
+        pub const SERVO_PREF_ENABLED_unicode_bidi: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_user_focus: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_user_input: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_user_modify: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_user_select: bool = false;
+        pub const SERVO_PREF_ENABLED_vector_effect: bool = false;
+        pub const SERVO_PREF_ENABLED_vertical_align: bool = false;
+        pub const SERVO_PREF_ENABLED_visibility: bool = false;
+        pub const SERVO_PREF_ENABLED_white_space: bool = false;
+        pub const SERVO_PREF_ENABLED_width: bool = false;
+        pub const SERVO_PREF_ENABLED_will_change: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_window_dragging: bool = false;
+        pub const SERVO_PREF_ENABLED__moz_window_shadow: bool = false;
+        pub const SERVO_PREF_ENABLED_word_break: bool = false;
+        pub const SERVO_PREF_ENABLED_word_spacing: bool = false;
+        pub const SERVO_PREF_ENABLED_overflow_wrap: bool = false;
+        pub const SERVO_PREF_ENABLED_writing_mode: bool = false;
+        pub const SERVO_PREF_ENABLED_z_index: bool = false;
         #[repr(C)]
         #[derive(Debug, Copy)]
         pub struct fallible_t {
diff --git a/components/style/properties/properties.mako.rs b/components/style/properties/properties.mako.rs
index 66cd5d3ae56..3661d03a39c 100644
--- a/components/style/properties/properties.mako.rs
+++ b/components/style/properties/properties.mako.rs
@@ -24,7 +24,8 @@ use error_reporting::ParseErrorReporter;
 use euclid::size::Size2D;
 use computed_values;
 use font_metrics::FontMetricsProvider;
-#[cfg(feature = "gecko")] use gecko_bindings::structs::nsCSSPropertyID;
+#[cfg(feature = "gecko")] use gecko_bindings::bindings;
+#[cfg(feature = "gecko")] use gecko_bindings::structs::{self, nsCSSPropertyID};
 #[cfg(feature = "servo")] use logical_geometry::{LogicalMargin, PhysicalSide};
 use logical_geometry::WritingMode;
 use parser::{Parse, ParserContext, ParserContextExtraData};
@@ -734,7 +735,16 @@ enum StaticId {
     Shorthand(ShorthandId),
 }
 include!(concat!(env!("OUT_DIR"), "/static_ids.rs"));
-
+<%
+    def alias_to_nscsspropertyid(alias):
+        if alias == "word-wrap":
+            return "nsCSSPropertyID_eCSSPropertyAlias_WordWrap"
+        return "nsCSSPropertyID::eCSSPropertyAlias_%s" % to_camel_case(alias)
+    def to_nscsspropertyid(ident):
+        if ident == "float":
+            ident = "float_"
+        return "nsCSSPropertyID::eCSSProperty_%s" % ident
+%>
 impl PropertyId {
     /// Returns a given property from the string `s`.
     ///
@@ -757,16 +767,6 @@ impl PropertyId {
     #[allow(non_upper_case_globals)]
     pub fn from_nscsspropertyid(id: nsCSSPropertyID) -> Result<Self, ()> {
         use gecko_bindings::structs::*;
-        <%
-            def alias_to_nscsspropertyid(alias):
-                if alias == "word-wrap":
-                    return "nsCSSPropertyID_eCSSPropertyAlias_WordWrap"
-                return "nsCSSPropertyID::eCSSPropertyAlias_%s" % to_camel_case(alias)
-            def to_nscsspropertyid(ident):
-                if ident == "float":
-                    ident = "float_"
-                return "nsCSSPropertyID::eCSSProperty_%s" % ident
-        %>
         match id {
             % for property in data.longhands:
                 ${to_nscsspropertyid(property.ident)} => {
@@ -792,6 +792,31 @@ impl PropertyId {
         }
     }
 
+    /// Returns a property id from Gecko's nsCSSPropertyID.
+    #[cfg(feature = "gecko")]
+    #[allow(non_upper_case_globals)]
+    pub fn to_nscsspropertyid(&self) -> Result<nsCSSPropertyID, ()> {
+        use gecko_bindings::structs::*;
+
+        match *self {
+            PropertyId::Longhand(id) => match id {
+                % for property in data.longhands:
+                    LonghandId::${property.camel_case} => {
+                        Ok(${to_nscsspropertyid(property.ident)})
+                    }
+                % endfor
+            },
+            PropertyId::Shorthand(id) => match id {
+                % for property in data.shorthands:
+                    ShorthandId::${property.camel_case} => {
+                        Ok(${to_nscsspropertyid(property.ident)})
+                    }
+                % endfor
+            },
+            _ => Err(())
+        }
+    }
+
     /// Given this property id, get it either as a shorthand or as a
     /// `PropertyDeclarationId`.
     pub fn as_shorthand(&self) -> Result<ShorthandId, PropertyDeclarationId> {
@@ -876,6 +901,33 @@ impl ToCss for PropertyDeclaration {
     }
 }
 
+<%def name="property_pref_check(property)">
+    % if property.experimental and product == "servo":
+        if !PREFS.get("${property.experimental}")
+            .as_boolean().unwrap_or(false) {
+            return PropertyDeclarationParseResult::ExperimentalProperty
+        }
+    % endif
+    % if product == "gecko":
+        <%
+            # gecko can't use the identifier `float`
+            # and instead uses `float_`
+            # XXXManishearth make this an attr on the property
+            # itself?
+            pref_ident = property.ident
+            if pref_ident == "float":
+                pref_ident = "float_"
+        %>
+        if structs::root::mozilla::SERVO_PREF_ENABLED_${pref_ident} {
+            let id = structs::${to_nscsspropertyid(property.ident)};
+            let enabled = unsafe { bindings::Gecko_PropertyId_IsPrefEnabled(id) };
+            if !enabled {
+                return PropertyDeclarationParseResult::ExperimentalProperty
+            }
+        }
+    % endif
+</%def>
+
 impl PropertyDeclaration {
     /// Given a property declaration, return the property declaration id.
     pub fn id(&self) -> PropertyDeclarationId {
@@ -978,12 +1030,9 @@ impl PropertyDeclaration {
                                 return PropertyDeclarationParseResult::UnknownProperty
                             }
                         % endif
-                        % if property.experimental and product == "servo":
-                            if !PREFS.get("${property.experimental}")
-                                .as_boolean().unwrap_or(false) {
-                                return PropertyDeclarationParseResult::ExperimentalProperty
-                            }
-                        % endif
+
+                        ${property_pref_check(property)}
+
                         match longhands::${property.ident}::parse_declared(context, input) {
                             Ok(value) => {
                                 result_list.push(PropertyDeclaration::${property.camel_case}(value));
@@ -1010,12 +1059,9 @@ impl PropertyDeclaration {
                             return PropertyDeclarationParseResult::UnknownProperty
                         }
                     % endif
-                    % if shorthand.experimental and product == "servo":
-                        if !PREFS.get("${shorthand.experimental}")
-                            .as_boolean().unwrap_or(false) {
-                            return PropertyDeclarationParseResult::ExperimentalProperty
-                        }
-                    % endif
+
+                    ${property_pref_check(shorthand)}
+
                     match input.try(|i| CSSWideKeyword::parse(context, i)) {
                         Ok(CSSWideKeyword::InheritKeyword) => {
                             % for sub_property in shorthand.sub_properties: