Auto merge of #19451 - emilio:inlining-is-fun, r=upsuper

style: Inline some things that should never ever appear in a profile.

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components/style/gecko/wrapper.rs

@@ -211,6 +211,7 @@ impl<'ln> GeckoNode<'ln> {
 
     /// WARNING: This logic is duplicated in Gecko's FlattenedTreeParentIsParent.
     /// Make sure to mirror any modifications in both places.
+    #[inline]
     fn flattened_tree_parent_is_parent(&self) -> bool {
         use gecko_bindings::structs::*;
         let flags = self.flags();
@@ -236,6 +237,7 @@ impl<'ln> GeckoNode<'ln> {
         true
     }
 
+    #[inline]
     fn flattened_tree_parent(&self) -> Option<Self> {
         let fast_path = self.flattened_tree_parent_is_parent();
         debug_assert!(fast_path == unsafe { bindings::Gecko_FlattenedTreeParentIsParent(self.0) });
@@ -246,6 +248,7 @@ impl<'ln> GeckoNode<'ln> {
         }
     }
 
+    #[inline]
     fn contains_non_whitespace_content(&self) -> bool {
         unsafe { Gecko_IsSignificantChild(self.0, true, false) }
     }

components/style/properties/declaration_block.rs

@@ -91,7 +91,7 @@ pub struct DeclarationImportanceIterator<'a> {
 }
 
 impl<'a> DeclarationImportanceIterator<'a> {
-    /// Constructor
+    /// Constructor.
     pub fn new(declarations: &'a [PropertyDeclaration], important: &'a SmallBitVec) -> Self {
         DeclarationImportanceIterator {
             iter: declarations.iter().zip(important.iter()),
@@ -102,17 +102,20 @@ impl<'a> DeclarationImportanceIterator<'a> {
 impl<'a> Iterator for DeclarationImportanceIterator<'a> {
     type Item = (&'a PropertyDeclaration, Importance);
 
+    #[inline]
     fn next(&mut self) -> Option<Self::Item> {
         self.iter.next().map(|(decl, important)|
             (decl, if important { Importance::Important } else { Importance::Normal }))
     }
 
+    #[inline]
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.iter.size_hint()
     }
 }
 
 impl<'a> DoubleEndedIterator for DeclarationImportanceIterator<'a> {
+    #[inline(always)]
     fn next_back(&mut self) -> Option<Self::Item> {
         self.iter.next_back().map(|(decl, important)|
             (decl, if important { Importance::Important } else { Importance::Normal }))
@@ -123,7 +126,8 @@ impl<'a> DoubleEndedIterator for DeclarationImportanceIterator<'a> {
 pub struct NormalDeclarationIterator<'a>(DeclarationImportanceIterator<'a>);
 
 impl<'a> NormalDeclarationIterator<'a> {
-    /// Constructor
+    /// Constructor.
+    #[inline]
     pub fn new(declarations: &'a [PropertyDeclaration], important: &'a SmallBitVec) -> Self {
         NormalDeclarationIterator(
             DeclarationImportanceIterator::new(declarations, important)

components/style/properties/properties.mako.rs

@@ -3129,6 +3129,9 @@ pub fn cascade(
 ) -> Arc<ComputedValues> {
     debug_assert_eq!(parent_style.is_some(), parent_style_ignoring_first_line.is_some());
     let empty = SmallBitVec::new();
+
+    let property_restriction = pseudo.and_then(|p| p.property_restriction());
+
     let iter_declarations = || {
         rule_node.self_and_ancestors().flat_map(|node| {
             let cascade_level = node.cascade_level();
@@ -3142,8 +3145,6 @@ pub fn cascade(
             };
             let node_importance = node.importance();
 
-            let property_restriction = pseudo.and_then(|p| p.property_restriction());
-
             declarations
                 // Yield declarations later in source order (with more precedence) first.
                 .rev()
@@ -3168,6 +3169,7 @@ pub fn cascade(
                 })
         })
     };
+
     apply_declarations(
         device,
         pseudo,
@@ -3187,7 +3189,6 @@ pub fn cascade(
 
 /// NOTE: This function expects the declaration with more priority to appear
 /// first.
-#[allow(unused_mut)] // conditionally compiled code for "position"
 pub fn apply_declarations<'a, F, I>(
     device: &Device,
     pseudo: Option<<&PseudoElement>,