style: Support matching :-moz-browser-frame and :-moz-table-border-nonzero against snapshots.

components/style/gecko/selector_parser.rs

@@ -206,6 +206,14 @@ impl NonTSPseudoClass {
         }
         apply_non_ts_list!(pseudo_class_geckotype)
     }
+
+    /// Returns true if the evaluation of the pseudo-class depends on the
+    /// element's attributes.
+    pub fn is_attr_based(&self) -> bool {
+        matches!(*self,
+                 NonTSPseudoClass::MozTableBorderNonzero |
+                 NonTSPseudoClass::MozBrowserFrame)
+    }
 }
 
 /// The dummy struct we use to implement our selector parsing.

components/style/gecko/snapshot.rs

@@ -55,6 +55,13 @@ impl GeckoElementSnapshot {
         self
     }
 
+    /// Returns true if the snapshot has stored state for pseudo-classes
+    /// that depend on things other than `ElementState`.
+    #[inline]
+    pub fn has_other_pseudo_class_state(&self) -> bool {
+        self.has_any(Flags::OtherPseudoClassState)
+    }
+
     /// selectors::Element::attr_matches
     pub fn attr_matches(&self,
                         ns: &NamespaceConstraint<&Namespace>,

components/style/restyle_hints.rs

@@ -679,6 +679,24 @@ impl<'a, E> Element for ElementWrapper<'a, E>
                 return relevant_link.is_visited(self, context);
             }
 
+            #[cfg(feature = "gecko")]
+            NonTSPseudoClass::MozTableBorderNonzero => {
+                if let Some(snapshot) = self.snapshot() {
+                    if snapshot.has_other_pseudo_class_state() {
+                        return snapshot.mIsTableBorderNonzero();
+                    }
+                }
+            }
+
+            #[cfg(feature = "gecko")]
+            NonTSPseudoClass::MozBrowserFrame => {
+                if let Some(snapshot) = self.snapshot() {
+                    if snapshot.has_other_pseudo_class_state() {
+                        return snapshot.mIsMozBrowserFrame();
+                    }
+                }
+            }
+
             _ => {}
         }
 
@@ -807,13 +825,14 @@ fn selector_to_state(sel: &Component<SelectorImpl>) -> ElementState {
     }
 }
 
-fn is_attr_selector(sel: &Component<SelectorImpl>) -> bool {
+fn is_attr_based_selector(sel: &Component<SelectorImpl>) -> bool {
     match *sel {
         Component::ID(_) |
         Component::Class(_) |
         Component::AttributeInNoNamespaceExists { .. } |
         Component::AttributeInNoNamespace { .. } |
         Component::AttributeOther(_) => true,
+        Component::NonTSPseudoClass(ref pc) => pc.is_attr_based(),
         _ => false,
     }
 }
@@ -902,7 +921,7 @@ impl SelectorVisitor for SensitivitiesVisitor {
     type Impl = SelectorImpl;
     fn visit_simple_selector(&mut self, s: &Component<SelectorImpl>) -> bool {
         self.sensitivities.states.insert(selector_to_state(s));
-        self.sensitivities.attrs |= is_attr_selector(s);
+        self.sensitivities.attrs |= is_attr_based_selector(s);
         true
     }
 }

components/style/servo/selector_parser.rs

@@ -268,6 +268,12 @@ impl NonTSPseudoClass {
     pub fn needs_cache_revalidation(&self) -> bool {
         self.state_flag().is_empty()
     }
+
+    /// Returns true if the evaluation of the pseudo-class depends on the
+    /// element's attributes.
+    pub fn is_attr_based(&self) -> bool {
+        false
+    }
 }
 
 /// The abstract struct we implement the selector parser implementation on top