style: Allow styles to be computed ignoring existing element data.

components/layout/query.rs

@@ -702,7 +702,7 @@ pub fn process_resolved_style_request<'a, N>(context: &LayoutContext,
         thread_local: &mut tlc,
     };
 
-    let styles = resolve_style(&mut context, element, RuleInclusion::All);
+    let styles = resolve_style(&mut context, element, RuleInclusion::All, false);
     let style = styles.primary();
     let longhand_id = match *property {
         PropertyId::Longhand(id) => id,

components/style/gecko/generated/bindings.rs

@@ -2810,7 +2810,8 @@ extern "C" {
                                     rule_inclusion: StyleRuleInclusion,
                                     snapshots:
                                         *const ServoElementSnapshotTable,
-                                    set: RawServoStyleSetBorrowed)
+                                    set: RawServoStyleSetBorrowed,
+                                    ignore_existing_styles: bool)
      -> ServoStyleContextStrong;
 }
 extern "C" {

components/style/traversal.rs

@@ -388,6 +388,7 @@ pub fn resolve_style<E>(
     context: &mut StyleContext<E>,
     element: E,
     rule_inclusion: RuleInclusion,
+    ignore_existing_style: bool,
 ) -> ElementStyles
 where
     E: TElement,
@@ -395,6 +396,7 @@ where
     use style_resolver::StyleResolverForElement;
 
     debug_assert!(rule_inclusion == RuleInclusion::DefaultOnly ||
+                  ignore_existing_style ||
                   element.borrow_data().map_or(true, |d| !d.has_styles()),
                   "Why are we here?");
     let mut ancestors_requiring_style_resolution = SmallVec::<[E; 16]>::new();
@@ -405,7 +407,7 @@ where
     let mut style = None;
     let mut ancestor = element.traversal_parent();
     while let Some(current) = ancestor {
-        if rule_inclusion == RuleInclusion::All {
+        if rule_inclusion == RuleInclusion::All && !ignore_existing_style {
             if let Some(data) = current.borrow_data() {
                 if let Some(ancestor_style) = data.styles.get_primary() {
                     style = Some(ancestor_style.clone());

ports/geckolib/glue.rs

@@ -2857,7 +2857,8 @@ pub extern "C" fn Servo_ResolveStyleLazily(element: RawGeckoElementBorrowed,
                                            pseudo_type: CSSPseudoElementType,
                                            rule_inclusion: StyleRuleInclusion,
                                            snapshots: *const ServoElementSnapshotTable,
-                                           raw_data: RawServoStyleSetBorrowed)
+                                           raw_data: RawServoStyleSetBorrowed,
+                                           ignore_existing_styles: bool)
      -> ServoStyleContextStrong
 {
     debug_assert!(!snapshots.is_null());
@@ -2888,8 +2889,9 @@ pub extern "C" fn Servo_ResolveStyleLazily(element: RawGeckoElementBorrowed,
 
     // In the common case we already have the style. Check that before setting
     // up all the computation machinery. (Don't use it when we're getting
-    // default styles, though.)
-    if rule_inclusion == RuleInclusion::All {
+    // default styles or in a bfcached document (as indicated by
+    // ignore_existing_styles), though.)
+    if rule_inclusion == RuleInclusion::All && !ignore_existing_styles {
         let styles = element.mutate_data().and_then(|d| {
             if d.has_styles() {
                 Some(finish(&d.styles))
@@ -2914,7 +2916,7 @@ pub extern "C" fn Servo_ResolveStyleLazily(element: RawGeckoElementBorrowed,
         thread_local: &mut tlc,
     };
 
-    let styles = resolve_style(&mut context, element, rule_inclusion);
+    let styles = resolve_style(&mut context, element, rule_inclusion, ignore_existing_styles);
     finish(&styles).into()
 }
 

tests/unit/gfx/font_cache_thread.rs

@@ -5,7 +5,7 @@
 use cssparser::SourceLocation;
 use gfx::font_cache_thread::FontCacheThread;
 use ipc_channel::ipc;
-use style::computed_values::font_family::FamilyName;
+use style::computed_values::font_family::{FamilyName, FamilyNameSyntax};
 use style::font_face::{FontFaceRuleData, Source};
 
 #[test]
@@ -15,11 +15,11 @@ fn test_local_web_font() {
     let font_cache_thread = FontCacheThread::new(inp_chan, None);
     let family_name = FamilyName {
         name: From::from("test family"),
-        quoted: true,
+        syntax: FamilyNameSyntax::Quoted,
     };
     let variant_name = FamilyName {
         name: From::from("test font face"),
-        quoted: true,
+        syntax: FamilyNameSyntax::Quoted,
     };
     let font_face_rule = FontFaceRuleData {
         family: Some(family_name.clone()),

tests/unit/style/stylesheets.rs

@@ -14,7 +14,7 @@ use servo_url::ServoUrl;
 use std::borrow::ToOwned;
 use std::sync::Mutex;
 use std::sync::atomic::AtomicBool;
-use style::computed_values::font_family::FamilyName;
+use style::computed_values::font_family::{FamilyName, FamilyNameSyntax};
 use style::context::QuirksMode;
 use style::error_reporting::{ParseErrorReporter, ContextualParseError};
 use style::media_queries::MediaList;
@@ -254,7 +254,7 @@ fn test_parse_stylesheet() {
                 CssRule::FontFeatureValues(Arc::new(stylesheet.shared_lock.wrap(FontFeatureValuesRule {
                     family_names: vec![FamilyName {
                         name: Atom::from("test"),
-                        quoted: false,
+                        syntax: FamilyNameSyntax::Identifiers(vec![Atom::from("test")]),
                     }],
                     swash: vec![
                         FFVDeclaration {