Auto merge of #13179 - servo:flatter-stylist, r=emilio

Remove one level of nesting in `Stylist`

<!-- Please describe your changes on the following line: -->

Since #13134, the "normal" and "important" parts of `Stylist` are identical, so we don’t need to store them twice.

r? @emilio

---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: -->
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [ ] These changes fix #__ (github issue number if applicable).

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- [ ] There are tests for these changes OR
- [x] These changes do not require tests because _____

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components/script/dom/element.rs

@@ -91,7 +91,7 @@ use style::properties::{DeclaredValue, Importance};
 use style::properties::{PropertyDeclaration, PropertyDeclarationBlock, parse_style_attribute};
 use style::refcell::Ref;
 use style::selector_impl::{NonTSPseudoClass, ServoSelectorImpl};
-use style::selector_matching::DeclarationBlock;
+use style::selector_matching::ApplicableDeclarationBlock;
 use style::sink::Push;
 use style::values::CSSFloat;
 use style::values::specified::{self, CSSColor, CSSRGBA, LengthOrPercentage};
@@ -291,7 +291,7 @@ pub trait LayoutElementHelpers {
 
     #[allow(unsafe_code)]
     unsafe fn synthesize_presentational_hints_for_legacy_attributes<V>(&self, &mut V)
-        where V: Push<DeclarationBlock>;
+        where V: Push<ApplicableDeclarationBlock>;
     #[allow(unsafe_code)]
     unsafe fn get_colspan(self) -> u32;
     #[allow(unsafe_code)]
@@ -324,11 +324,11 @@ impl LayoutElementHelpers for LayoutJS<Element> {
 
     #[allow(unsafe_code)]
     unsafe fn synthesize_presentational_hints_for_legacy_attributes<V>(&self, hints: &mut V)
-        where V: Push<DeclarationBlock>
+        where V: Push<ApplicableDeclarationBlock>
     {
         #[inline]
-        fn from_declaration(rule: PropertyDeclaration) -> DeclarationBlock {
-            DeclarationBlock::from_declarations(
+        fn from_declaration(rule: PropertyDeclaration) -> ApplicableDeclarationBlock {
+            ApplicableDeclarationBlock::from_declarations(
                 Arc::new(PropertyDeclarationBlock {
                     declarations: vec![(rule, Importance::Normal)],
                     important_count: 0,

components/script/layout_wrapper.rs

@@ -63,7 +63,7 @@ use style::element_state::*;
 use style::properties::{ComputedValues, PropertyDeclarationBlock};
 use style::refcell::{Ref, RefCell, RefMut};
 use style::selector_impl::{ElementSnapshot, NonTSPseudoClass, PseudoElement, ServoSelectorImpl};
-use style::selector_matching::DeclarationBlock;
+use style::selector_matching::ApplicableDeclarationBlock;
 use style::sink::Push;
 use style::str::is_whitespace;
 use url::Url;
@@ -442,7 +442,7 @@ impl<'le> fmt::Debug for ServoLayoutElement<'le> {
 
 impl<'le> PresentationalHintsSynthetizer for ServoLayoutElement<'le> {
     fn synthesize_presentational_hints_for_legacy_attributes<V>(&self, hints: &mut V)
-        where V: Push<DeclarationBlock>
+        where V: Push<ApplicableDeclarationBlock>
     {
         unsafe {
             self.element.synthesize_presentational_hints_for_legacy_attributes(hints);
@@ -1094,5 +1094,5 @@ impl<'le> ::selectors::Element for ServoThreadSafeLayoutElement<'le> {
 
 impl<'le> PresentationalHintsSynthetizer for ServoThreadSafeLayoutElement<'le> {
     fn synthesize_presentational_hints_for_legacy_attributes<V>(&self, _hints: &mut V)
-        where V: Push<DeclarationBlock> {}
+        where V: Push<ApplicableDeclarationBlock> {}
 }

components/style/animation.rs

@@ -16,7 +16,7 @@ use properties::longhands::animation_play_state::computed_value::AnimationPlaySt
 use properties::longhands::transition_timing_function::computed_value::StartEnd;
 use properties::longhands::transition_timing_function::computed_value::TransitionTimingFunction;
 use properties::{self, ComputedValues, Importance};
-use selector_matching::DeclarationBlock;
+use selector_matching::ApplicableDeclarationBlock;
 use std::sync::Arc;
 use std::sync::mpsc::Sender;
 use string_cache::Atom;
@@ -384,7 +384,7 @@ fn compute_style_for_animation_step(context: &SharedStyleContext,
         // an Arc in the below (more common case).
         KeyframesStepValue::ComputedValues => style_from_cascade.clone(),
         KeyframesStepValue::Declarations(ref declarations) => {
-            let declaration_block = DeclarationBlock {
+            let declaration_block = ApplicableDeclarationBlock {
                 mixed_declarations: declarations.clone(),
                 importance: Importance::Normal,
                 source_order: 0,

components/style/dom.rs

@@ -13,7 +13,7 @@ use properties::{ComputedValues, PropertyDeclarationBlock};
 use refcell::{Ref, RefMut};
 use restyle_hints::{RESTYLE_DESCENDANTS, RESTYLE_LATER_SIBLINGS, RESTYLE_SELF, RestyleHint};
 use selector_impl::{ElementExt, PseudoElement};
-use selector_matching::DeclarationBlock;
+use selector_matching::ApplicableDeclarationBlock;
 use sink::Push;
 use std::fmt::Debug;
 use std::ops::BitOr;
@@ -186,7 +186,7 @@ pub trait TDocument : Sized + Copy + Clone {
 
 pub trait PresentationalHintsSynthetizer {
     fn synthesize_presentational_hints_for_legacy_attributes<V>(&self, hints: &mut V)
-        where V: Push<DeclarationBlock>;
+        where V: Push<ApplicableDeclarationBlock>;
 }
 
 pub trait TElement : PartialEq + Debug + Sized + Copy + Clone + ElementExt + PresentationalHintsSynthetizer {

components/style/keyframes.rs

@@ -75,7 +75,7 @@ pub struct Keyframe {
 
     /// `!important` is not allowed in keyframe declarations,
     /// so the second value of these tuples is always `Importance::Normal`.
-    /// But including them enables `compute_style_for_animation_step` to create a `DeclarationBlock`
+    /// But including them enables `compute_style_for_animation_step` to create a `ApplicableDeclarationBlock`
     /// by cloning an `Arc<_>` (incrementing a reference count) rather than re-creating a `Vec<_>`.
     pub block: Arc<PropertyDeclarationBlock>,
 }

components/style/matching.rs

@@ -16,7 +16,7 @@ use dom::{TElement, TNode, TRestyleDamage, UnsafeNode};
 use properties::longhands::display::computed_value as display;
 use properties::{ComputedValues, cascade, PropertyDeclarationBlock};
 use selector_impl::{TheSelectorImpl, PseudoElement};
-use selector_matching::{DeclarationBlock, Stylist};
+use selector_matching::{ApplicableDeclarationBlock, Stylist};
 use selectors::bloom::BloomFilter;
 use selectors::matching::{MatchingReason, StyleRelations, AFFECTED_BY_PSEUDO_ELEMENTS};
 use selectors::{Element, MatchAttr};
@@ -51,9 +51,9 @@ fn create_common_style_affecting_attributes_from_element<E: TElement>(element: &
 }
 
 pub struct ApplicableDeclarations {
-    pub normal: SmallVec<[DeclarationBlock; 16]>,
+    pub normal: SmallVec<[ApplicableDeclarationBlock; 16]>,
     pub per_pseudo: HashMap<PseudoElement,
-                            Vec<DeclarationBlock>,
+                            Vec<ApplicableDeclarationBlock>,
                             BuildHasherDefault<::fnv::FnvHasher>>,
 
     /// Whether the `normal` declarations are shareable with other nodes.
@@ -78,11 +78,11 @@ impl ApplicableDeclarations {
 
 #[derive(Clone)]
 pub struct ApplicableDeclarationsCacheEntry {
-    pub declarations: Vec<DeclarationBlock>,
+    pub declarations: Vec<ApplicableDeclarationBlock>,
 }
 
 impl ApplicableDeclarationsCacheEntry {
-    fn new(declarations: Vec<DeclarationBlock>) -> ApplicableDeclarationsCacheEntry {
+    fn new(declarations: Vec<ApplicableDeclarationBlock>) -> ApplicableDeclarationsCacheEntry {
         ApplicableDeclarationsCacheEntry {
             declarations: declarations,
         }
@@ -105,11 +105,11 @@ impl Hash for ApplicableDeclarationsCacheEntry {
 }
 
 struct ApplicableDeclarationsCacheQuery<'a> {
-    declarations: &'a [DeclarationBlock],
+    declarations: &'a [ApplicableDeclarationBlock],
 }
 
 impl<'a> ApplicableDeclarationsCacheQuery<'a> {
-    fn new(declarations: &'a [DeclarationBlock]) -> ApplicableDeclarationsCacheQuery<'a> {
+    fn new(declarations: &'a [ApplicableDeclarationBlock]) -> ApplicableDeclarationsCacheQuery<'a> {
         ApplicableDeclarationsCacheQuery {
             declarations: declarations,
         }
@@ -159,14 +159,14 @@ impl ApplicableDeclarationsCache {
         }
     }
 
-    pub fn find(&self, declarations: &[DeclarationBlock]) -> Option<Arc<ComputedValues>> {
+    pub fn find(&self, declarations: &[ApplicableDeclarationBlock]) -> Option<Arc<ComputedValues>> {
         match self.cache.find(&ApplicableDeclarationsCacheQuery::new(declarations)) {
             None => None,
             Some(ref values) => Some((*values).clone()),
         }
     }
 
-    pub fn insert(&mut self, declarations: Vec<DeclarationBlock>, style: Arc<ComputedValues>) {
+    pub fn insert(&mut self, declarations: Vec<ApplicableDeclarationBlock>, style: Arc<ComputedValues>) {
         self.cache.insert(ApplicableDeclarationsCacheEntry::new(declarations), style)
     }
 
@@ -493,7 +493,7 @@ trait PrivateMatchMethods: TNode {
     fn cascade_node_pseudo_element<'a, Ctx>(&self,
                                             context: &Ctx,
                                             parent_style: Option<&Arc<ComputedValues>>,
-                                            applicable_declarations: &[DeclarationBlock],
+                                            applicable_declarations: &[ApplicableDeclarationBlock],
                                             mut old_style: Option<&mut Arc<ComputedValues>>,
                                             applicable_declarations_cache:
                                              &mut ApplicableDeclarationsCache,

components/style/properties/properties.mako.rs

@@ -29,7 +29,7 @@ use computed_values;
 #[cfg(feature = "servo")] use logical_geometry::{LogicalMargin, PhysicalSide};
 use logical_geometry::WritingMode;
 use parser::{ParserContext, ParserContextExtraData, log_css_error};
-use selector_matching::DeclarationBlock;
+use selector_matching::ApplicableDeclarationBlock;
 use stylesheets::Origin;
 use values::LocalToCss;
 use values::HasViewportPercentage;
@@ -1718,7 +1718,7 @@ mod lazy_static_module {
 #[allow(unused_mut, unused_imports)]
 fn cascade_with_cached_declarations(
         viewport_size: Size2D<Au>,
-        applicable_declarations: &[DeclarationBlock],
+        applicable_declarations: &[ApplicableDeclarationBlock],
         shareable: bool,
         parent_style: &ComputedValues,
         cached_style: &ComputedValues,
@@ -1863,7 +1863,7 @@ static CASCADE_PROPERTY: [CascadePropertyFn; ${len(data.longhands)}] = [
 ///
 /// Returns the computed values and a boolean indicating whether the result is cacheable.
 pub fn cascade(viewport_size: Size2D<Au>,
-               applicable_declarations: &[DeclarationBlock],
+               applicable_declarations: &[ApplicableDeclarationBlock],
                shareable: bool,
                parent_style: Option<<&ComputedValues>,
                cached_style: Option<<&ComputedValues>,