style: Enable chrome-only CSS features in user stylesheets.

MozReview-Commit-ID: FJ4vTiOrotH
Reviewed-by: heycam
Bug: 1418963

components/style/gecko/media_queries.rs

@@ -588,7 +588,7 @@ impl Expression {
 
                 let mut flags = 0;
 
-                if context.in_chrome_stylesheet() ||
+                if context.chrome_rules_enabled() ||
                     context.stylesheet_origin == Origin::UserAgent {
                     flags |= structs::nsMediaFeature_RequirementFlags_eUserAgentAndChromeOnly;
                 }

components/style/gecko/selector_parser.rs

@@ -295,14 +295,27 @@ impl ::selectors::SelectorImpl for SelectorImpl {
 }
 
 impl<'a> SelectorParser<'a> {
-    fn is_pseudo_class_enabled(&self,
-                               pseudo_class: &NonTSPseudoClass)
-                               -> bool {
-        pseudo_class.is_enabled_in_content() ||
-            (self.in_user_agent_stylesheet() &&
-             pseudo_class.has_any_flag(NonTSPseudoClassFlag::PSEUDO_CLASS_ENABLED_IN_UA_SHEETS)) ||
-            (self.in_chrome_stylesheet() &&
-             pseudo_class.has_any_flag(NonTSPseudoClassFlag::PSEUDO_CLASS_ENABLED_IN_CHROME))
+    fn is_pseudo_class_enabled(
+        &self,
+        pseudo_class: &NonTSPseudoClass,
+    ) -> bool {
+        if pseudo_class.is_enabled_in_content() {
+            return true;
+        }
+
+        if self.in_user_agent_stylesheet() &&
+           pseudo_class.has_any_flag(NonTSPseudoClassFlag::PSEUDO_CLASS_ENABLED_IN_UA_SHEETS)
+        {
+            return true;
+        }
+
+        if self.chrome_rules_enabled() &&
+           pseudo_class.has_any_flag(NonTSPseudoClassFlag::PSEUDO_CLASS_ENABLED_IN_CHROME)
+        {
+            return true;
+        }
+
+        return false;
     }
 }
 
@@ -315,8 +328,11 @@ impl<'a, 'i> ::selectors::Parser<'i> for SelectorParser<'a> {
             name.starts_with("-moz-tree-") // tree pseudo-elements
     }
 
-    fn parse_non_ts_pseudo_class(&self, location: SourceLocation, name: CowRcStr<'i>)
-                                 -> Result<NonTSPseudoClass, ParseError<'i>> {
+    fn parse_non_ts_pseudo_class(
+        &self,
+        location: SourceLocation,
+        name: CowRcStr<'i>,
+    ) -> Result<NonTSPseudoClass, ParseError<'i>> {
         macro_rules! pseudo_class_parse {
             (bare: [$(($css:expr, $name:ident, $gecko_type:tt, $state:tt, $flags:tt),)*],
              string: [$(($s_css:expr, $s_name:ident, $s_gecko_type:tt, $s_state:tt, $s_flags:tt),)*],
@@ -337,10 +353,11 @@ impl<'a, 'i> ::selectors::Parser<'i> for SelectorParser<'a> {
         }
     }
 
-    fn parse_non_ts_functional_pseudo_class<'t>(&self,
-                                                name: CowRcStr<'i>,
-                                                parser: &mut Parser<'i, 't>)
-                                                -> Result<NonTSPseudoClass, ParseError<'i>> {
+    fn parse_non_ts_functional_pseudo_class<'t>(
+        &self,
+        name: CowRcStr<'i>,
+        parser: &mut Parser<'i, 't>,
+    ) -> Result<NonTSPseudoClass, ParseError<'i>> {
         macro_rules! pseudo_class_string_parse {
             (bare: [$(($css:expr, $name:ident, $gecko_type:tt, $state:tt, $flags:tt),)*],
              string: [$(($s_css:expr, $s_name:ident, $s_gecko_type:tt, $s_state:tt, $s_flags:tt),)*],
@@ -386,8 +403,11 @@ impl<'a, 'i> ::selectors::Parser<'i> for SelectorParser<'a> {
         }
     }
 
-    fn parse_pseudo_element(&self, location: SourceLocation, name: CowRcStr<'i>)
-                            -> Result<PseudoElement, ParseError<'i>> {
+    fn parse_pseudo_element(
+        &self,
+        location: SourceLocation,
+        name: CowRcStr<'i>,
+    ) -> Result<PseudoElement, ParseError<'i>> {
         PseudoElement::from_slice(&name, self.in_user_agent_stylesheet())
             .or_else(|| {
                 if name.starts_with("-moz-tree-") {
@@ -399,9 +419,11 @@ impl<'a, 'i> ::selectors::Parser<'i> for SelectorParser<'a> {
             .ok_or(location.new_custom_error(SelectorParseErrorKind::UnsupportedPseudoClassOrElement(name.clone())))
     }
 
-    fn parse_functional_pseudo_element<'t>(&self, name: CowRcStr<'i>,
-                                           parser: &mut Parser<'i, 't>)
-                                           -> Result<PseudoElement, ParseError<'i>> {
+    fn parse_functional_pseudo_element<'t>(
+        &self,
+        name: CowRcStr<'i>,
+        parser: &mut Parser<'i, 't>,
+    ) -> Result<PseudoElement, ParseError<'i>> {
         if name.starts_with("-moz-tree-") {
             // Tree pseudo-elements can have zero or more arguments,
             // separated by either comma or space.

components/style/parser.rs

@@ -132,9 +132,9 @@ impl<'a> ParserContext<'a> {
         context.error_reporter.report_error(self.url_data, location, error)
     }
 
-    /// Returns whether this is a chrome stylesheets.
-    pub fn in_chrome_stylesheet(&self) -> bool {
-        self.url_data.is_chrome()
+    /// Returns whether chrome-only rules should be parsed.
+    pub fn chrome_rules_enabled(&self) -> bool {
+        self.url_data.is_chrome() || self.stylesheet_origin == Origin::User
     }
 }
 

components/style/properties/properties.mako.rs

@@ -1158,7 +1158,7 @@ impl PropertyId {
             Some(context) => context,
             None => {
                 default = PropertyParserContext {
-                    in_chrome_stylesheet: false,
+                    chrome_rules_enabled: false,
                     stylesheet_origin: Origin::Author,
                     rule_type: CssRuleType::Style,
                 };
@@ -1346,7 +1346,7 @@ impl PropertyId {
             return Ok(())
         }
 
-        if context.in_chrome_stylesheet && ENABLED_IN_CHROME.contains(id) {
+        if context.chrome_rules_enabled && ENABLED_IN_CHROME.contains(id) {
             return Ok(())
         }
 
@@ -1357,7 +1357,7 @@ impl PropertyId {
 /// Parsing Context for PropertyId.
 pub struct PropertyParserContext {
     /// Whether the property is parsed in a chrome:// stylesheet.
-    pub in_chrome_stylesheet: bool,
+    pub chrome_rules_enabled: bool,
     /// The Origin of the stylesheet, whether it's a user,
     /// author or user-agent stylesheet.
     pub stylesheet_origin: Origin,
@@ -1369,7 +1369,7 @@ impl PropertyParserContext {
     /// Creates a PropertyParserContext with given stylesheet origin and rule type.
     pub fn new(context: &ParserContext) -> Self {
         Self {
-            in_chrome_stylesheet: context.in_chrome_stylesheet(),
+            chrome_rules_enabled: context.chrome_rules_enabled(),
             stylesheet_origin: context.stylesheet_origin,
             rule_type: context.rule_type(),
         }

components/style/selector_parser.rs

@@ -70,8 +70,9 @@ impl<'a> SelectorParser<'a> {
 
     /// Whether we're parsing selectors in a stylesheet that has chrome
     /// privilege.
-    pub fn in_chrome_stylesheet(&self) -> bool {
-        self.url_data.map_or(false, |d| d.is_chrome())
+    pub fn chrome_rules_enabled(&self) -> bool {
+        self.url_data.map_or(false, |d| d.is_chrome()) ||
+            self.stylesheet_origin == Origin::User
     }
 }