Servo glue for @page rule

Expose new glue functions and types on the Servo side for working with @page
rules from Gecko.

MozReview-Commit-ID: 5g13YldTr9

components/style/gecko/arc_types.rs

@@ -8,7 +8,7 @@
 
 #![allow(non_snake_case, missing_docs)]
 
-use gecko_bindings::bindings::{RawServoMediaList, RawServoMediaRule, RawServoNamespaceRule};
+use gecko_bindings::bindings::{RawServoMediaList, RawServoMediaRule, RawServoNamespaceRule, RawServoPageRule};
 use gecko_bindings::bindings::{RawServoStyleSheet, RawServoStyleRule, RawServoImportRule};
 use gecko_bindings::bindings::{ServoComputedValues, ServoCssRules};
 use gecko_bindings::structs::{RawServoAnimationValue, RawServoAnimationValueMap, RawServoDeclarationBlock};
@@ -18,7 +18,7 @@ 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};
+use stylesheets::{CssRules, Stylesheet, StyleRule, ImportRule, MediaRule, NamespaceRule, PageRule};
 
 macro_rules! impl_arc_ffi {
     ($servo_type:ty => $gecko_type:ty [$addref:ident, $release:ident]) => {
@@ -71,3 +71,6 @@ impl_arc_ffi!(Locked<MediaRule> => RawServoMediaRule
 
 impl_arc_ffi!(Locked<NamespaceRule> => RawServoNamespaceRule
               [Servo_NamespaceRule_AddRef, Servo_NamespaceRule_Release]);
+
+impl_arc_ffi!(Locked<PageRule> => RawServoPageRule
+              [Servo_PageRule_AddRef, Servo_PageRule_Release]);

ports/geckolib/glue.rs

@@ -32,6 +32,7 @@ use style::gecko_bindings::bindings::{RawServoDeclarationBlockBorrowed, RawServo
 use style::gecko_bindings::bindings::{RawServoMediaListBorrowed, RawServoMediaListStrong};
 use style::gecko_bindings::bindings::{RawServoMediaRule, RawServoMediaRuleBorrowed};
 use style::gecko_bindings::bindings::{RawServoNamespaceRule, RawServoNamespaceRuleBorrowed};
+use style::gecko_bindings::bindings::{RawServoPageRule, RawServoPageRuleBorrowed};
 use style::gecko_bindings::bindings::{RawServoStyleRule, RawServoStyleRuleBorrowed};
 use style::gecko_bindings::bindings::{RawServoStyleSetBorrowed, RawServoStyleSetOwned};
 use style::gecko_bindings::bindings::{RawServoStyleSheetBorrowed, ServoComputedValuesBorrowed};
@@ -79,7 +80,7 @@ use style::selector_parser::PseudoElementCascadeType;
 use style::sequential;
 use style::shared_lock::{SharedRwLock, SharedRwLockReadGuard, StylesheetGuards, ToCssWithGuard, Locked};
 use style::string_cache::Atom;
-use style::stylesheets::{CssRule, CssRules, CssRuleType, ImportRule, MediaRule, NamespaceRule};
+use style::stylesheets::{CssRule, CssRules, CssRuleType, ImportRule, MediaRule, NamespaceRule, PageRule};
 use style::stylesheets::{Origin, Stylesheet, StyleRule};
 use style::stylesheets::StylesheetLoader as StyleStylesheetLoader;
 use style::supports::parse_condition_or_declaration;
@@ -731,6 +732,12 @@ impl_basic_rule_funcs! { (Namespace, NamespaceRule, RawServoNamespaceRule),
     to_css: Servo_NamespaceRule_GetCssText,
 }
 
+impl_basic_rule_funcs! { (Page, PageRule, RawServoPageRule),
+    getter: Servo_CssRules_GetPageRuleAt,
+    debug: Servo_PageRule_Debug,
+    to_css: Servo_PageRule_GetCssText,
+}
+
 #[no_mangle]
 pub extern "C" fn Servo_CssRules_GetFontFaceRuleAt(rules: ServoCssRulesBorrowed, index: u32)
                                                    -> *mut nsCSSFontFaceRule
@@ -793,6 +800,22 @@ pub extern "C" fn Servo_NamespaceRule_GetURI(rule: RawServoNamespaceRuleBorrowed
     read_locked_arc(rule, |rule: &NamespaceRule| rule.url.0.as_ptr())
 }
 
+#[no_mangle]
+pub extern "C" fn Servo_PageRule_GetStyle(rule: RawServoPageRuleBorrowed) -> RawServoDeclarationBlockStrong {
+    read_locked_arc(rule, |rule: &PageRule| {
+        rule.0.clone().into_strong()
+    })
+}
+
+#[no_mangle]
+pub extern "C" fn Servo_PageRule_SetStyle(rule: RawServoPageRuleBorrowed,
+                                           declarations: RawServoDeclarationBlockBorrowed) {
+    let declarations = Locked::<PropertyDeclarationBlock>::as_arc(&declarations);
+    write_locked_arc(rule, |rule: &mut PageRule| {
+        rule.0 = declarations.clone();
+    })
+}
+
 #[no_mangle]
 pub extern "C" fn Servo_ComputedValues_GetForAnonymousBox(parent_style_or_null: ServoComputedValuesBorrowedOrNull,
                                                           pseudo_tag: *mut nsIAtom,