Implement CSSOM support for @supports.

components/style/gecko/arc_types.rs

@@ -9,7 +9,7 @@
 #![allow(non_snake_case, missing_docs)]
 
 use gecko_bindings::bindings::{RawServoMediaList, RawServoMediaRule, RawServoNamespaceRule, RawServoPageRule};
-use gecko_bindings::bindings::{RawServoStyleSheet, RawServoImportRule};
+use gecko_bindings::bindings::{RawServoStyleSheet, RawServoImportRule, RawServoSupportsRule};
 use gecko_bindings::bindings::{ServoComputedValues, ServoCssRules};
 use gecko_bindings::structs::{RawServoAnimationValue, RawServoAnimationValueMap};
 use gecko_bindings::structs::{RawServoDeclarationBlock, RawServoStyleRule};
@@ -19,7 +19,8 @@ use parking_lot::RwLock;
 use properties::{ComputedValues, PropertyDeclarationBlock};
 use properties::animated_properties::{AnimationValue, AnimationValueMap};
 use shared_lock::Locked;
-use stylesheets::{CssRules, Stylesheet, StyleRule, ImportRule, MediaRule, NamespaceRule, PageRule};
+use stylesheets::{CssRules, Stylesheet, StyleRule, ImportRule, MediaRule};
+use stylesheets::{NamespaceRule, PageRule, SupportsRule};
 
 macro_rules! impl_arc_ffi {
     ($servo_type:ty => $gecko_type:ty [$addref:ident, $release:ident]) => {
@@ -75,3 +76,6 @@ impl_arc_ffi!(Locked<NamespaceRule> => RawServoNamespaceRule
 
 impl_arc_ffi!(Locked<PageRule> => RawServoPageRule
               [Servo_PageRule_AddRef, Servo_PageRule_Release]);
+
+impl_arc_ffi!(Locked<SupportsRule> => RawServoSupportsRule
+              [Servo_SupportsRule_AddRef, Servo_SupportsRule_Release]);

ports/geckolib/glue.rs

@@ -36,6 +36,7 @@ use style::gecko_bindings::bindings::{RawServoPageRule, RawServoPageRuleBorrowed
 use style::gecko_bindings::bindings::{RawServoStyleSetBorrowed, RawServoStyleSetOwned};
 use style::gecko_bindings::bindings::{RawServoStyleSheetBorrowed, ServoComputedValuesBorrowed};
 use style::gecko_bindings::bindings::{RawServoStyleSheetStrong, ServoComputedValuesStrong};
+use style::gecko_bindings::bindings::{RawServoSupportsRule, RawServoSupportsRuleBorrowed};
 use style::gecko_bindings::bindings::{ServoCssRulesBorrowed, ServoCssRulesStrong};
 use style::gecko_bindings::bindings::{nsACString, nsAString};
 use style::gecko_bindings::bindings::Gecko_AnimationAppendKeyframe;
@@ -84,7 +85,7 @@ use style::shared_lock::{SharedRwLock, SharedRwLockReadGuard, StylesheetGuards,
 use style::string_cache::Atom;
 use style::stylesheets::{CssRule, CssRules, CssRuleType, CssRulesHelpers};
 use style::stylesheets::{ImportRule, MediaRule, NamespaceRule, Origin};
-use style::stylesheets::{PageRule, Stylesheet, StyleRule};
+use style::stylesheets::{PageRule, Stylesheet, StyleRule, SupportsRule};
 use style::stylesheets::StylesheetLoader as StyleStylesheetLoader;
 use style::supports::parse_condition_or_declaration;
 use style::thread_state;
@@ -821,6 +822,13 @@ impl_basic_rule_funcs! { (Page, PageRule, RawServoPageRule),
     to_css: Servo_PageRule_GetCssText,
 }
 
+impl_group_rule_funcs! { (Supports, SupportsRule, RawServoSupportsRule),
+    get_rules: Servo_SupportsRule_GetRules,
+    getter: Servo_CssRules_GetSupportsRuleAt,
+    debug: Servo_SupportsRule_Debug,
+    to_css: Servo_SupportsRule_GetCssText,
+}
+
 #[no_mangle]
 pub extern "C" fn Servo_CssRules_GetFontFaceRuleAt(rules: ServoCssRulesBorrowed, index: u32)
                                                    -> *mut nsCSSFontFaceRule
@@ -892,6 +900,14 @@ pub extern "C" fn Servo_PageRule_SetStyle(rule: RawServoPageRuleBorrowed,
     })
 }
 
+#[no_mangle]
+pub extern "C" fn Servo_SupportsRule_GetConditionText(rule: RawServoSupportsRuleBorrowed,
+                                                      result: *mut nsAString) {
+    read_locked_arc(rule, |rule: &SupportsRule| {
+        rule.condition.to_css(unsafe { result.as_mut().unwrap() }).unwrap();
+    })
+}
+
 #[no_mangle]
 pub extern "C" fn Servo_ComputedValues_GetForAnonymousBox(parent_style_or_null: ServoComputedValuesBorrowedOrNull,
                                                           pseudo_tag: *mut nsIAtom,