Auto merge of #16642 - upsuper:bug1355394, r=heycam

stylo: Implement access to CSSSupportsRule

Servo side change of [bug 1355394](https://bugzilla.mozilla.org/show_bug.cgi?id=1355394).

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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]);

components/style/gecko_bindings/bindings.rs

@@ -244,6 +244,11 @@ pub type RawServoPageRuleBorrowed<'a> = &'a RawServoPageRule;
 pub type RawServoPageRuleBorrowedOrNull<'a> = Option<&'a RawServoPageRule>;
 enum RawServoPageRuleVoid { }
 pub struct RawServoPageRule(RawServoPageRuleVoid);
+pub type RawServoSupportsRuleStrong = ::gecko_bindings::sugar::ownership::Strong<RawServoSupportsRule>;
+pub type RawServoSupportsRuleBorrowed<'a> = &'a RawServoSupportsRule;
+pub type RawServoSupportsRuleBorrowedOrNull<'a> = Option<&'a RawServoSupportsRule>;
+enum RawServoSupportsRuleVoid { }
+pub struct RawServoSupportsRule(RawServoSupportsRuleVoid);
 pub type RawServoStyleSetOwned = ::gecko_bindings::sugar::ownership::Owned<RawServoStyleSet>;
 pub type RawServoStyleSetOwnedOrNull = ::gecko_bindings::sugar::ownership::OwnedOrNull<RawServoStyleSet>;
 pub type RawServoStyleSetBorrowed<'a> = &'a RawServoStyleSet;
@@ -399,6 +404,12 @@ extern "C" {
 extern "C" {
     pub fn Servo_PageRule_Release(ptr: RawServoPageRuleBorrowed);
 }
+extern "C" {
+    pub fn Servo_SupportsRule_AddRef(ptr: RawServoSupportsRuleBorrowed);
+}
+extern "C" {
+    pub fn Servo_SupportsRule_Release(ptr: RawServoSupportsRuleBorrowed);
+}
 extern "C" {
     pub fn Servo_StyleSet_Drop(ptr: RawServoStyleSetOwned);
 }
@@ -1665,6 +1676,10 @@ extern "C" {
     pub fn Servo_MediaRule_GetCssText(rule: RawServoMediaRuleBorrowed,
                                       result: *mut nsAString);
 }
+extern "C" {
+    pub fn Servo_MediaRule_GetRules(rule: RawServoMediaRuleBorrowed)
+     -> ServoCssRulesStrong;
+}
 extern "C" {
     pub fn Servo_CssRules_GetNamespaceRuleAt(rules: ServoCssRulesBorrowed,
                                              index: u32)
@@ -1690,6 +1705,23 @@ extern "C" {
     pub fn Servo_PageRule_GetCssText(rule: RawServoPageRuleBorrowed,
                                      result: *mut nsAString);
 }
+extern "C" {
+    pub fn Servo_CssRules_GetSupportsRuleAt(rules: ServoCssRulesBorrowed,
+                                            index: u32)
+     -> RawServoSupportsRuleStrong;
+}
+extern "C" {
+    pub fn Servo_SupportsRule_Debug(rule: RawServoSupportsRuleBorrowed,
+                                    result: *mut nsACString);
+}
+extern "C" {
+    pub fn Servo_SupportsRule_GetCssText(rule: RawServoSupportsRuleBorrowed,
+                                         result: *mut nsAString);
+}
+extern "C" {
+    pub fn Servo_SupportsRule_GetRules(rule: RawServoSupportsRuleBorrowed)
+     -> ServoCssRulesStrong;
+}
 extern "C" {
     pub fn Servo_CssRules_GetFontFaceRuleAt(rules: ServoCssRulesBorrowed,
                                             index: u32)
@@ -1712,10 +1744,6 @@ extern "C" {
     pub fn Servo_MediaRule_GetMedia(rule: RawServoMediaRuleBorrowed)
      -> RawServoMediaListStrong;
 }
-extern "C" {
-    pub fn Servo_MediaRule_GetRules(rule: RawServoMediaRuleBorrowed)
-     -> ServoCssRulesStrong;
-}
 extern "C" {
     pub fn Servo_NamespaceRule_GetPrefix(rule: RawServoNamespaceRuleBorrowed)
      -> *mut nsIAtom;
@@ -1733,6 +1761,11 @@ extern "C" {
                                    declarations:
                                        RawServoDeclarationBlockBorrowed);
 }
+extern "C" {
+    pub fn Servo_SupportsRule_GetConditionText(rule:
+                                                   RawServoSupportsRuleBorrowed,
+                                               result: *mut nsAString);
+}
 extern "C" {
     pub fn Servo_ParseProperty(property: nsCSSPropertyID,
                                value: *const nsACString,