Auto merge of #15269 - Maaarcocr:master, r=emilio

Substituing quickersort with pdqsort

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I have been working on issue number #15244. I have substituted quickersort with pdqsort in the style component. The changes I made affect: Cargo.toml, stylist.rs and lib.rs (all of them are in /components/style).

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- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix #15244 (github issue number if applicable).

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- [ ] There are tests for these changes OR
- [X] These changes do not require tests because both library expose the same functionality, they differ in permance.

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components/style/Cargo.toml

@@ -43,7 +43,7 @@ ordered-float = "0.2.2"
 owning_ref = "0.2.2"
 parking_lot = "0.3.3"
 phf = "0.7.20"
-quickersort = "2.0.0"
+pdqsort = "0.1.0"
 rayon = "0.6"
 rustc-serialize = "0.3"
 selectors = "0.15.1"

components/style/lib.rs

@@ -65,8 +65,8 @@ extern crate num_traits;
 extern crate ordered_float;
 extern crate owning_ref;
 extern crate parking_lot;
+extern crate pdqsort;
 extern crate phf;
-extern crate quickersort;
 extern crate rayon;
 extern crate rustc_serialize;
 extern crate selectors;

components/style/stylist.rs

@@ -13,9 +13,9 @@ use error_reporting::StdoutErrorReporter;
 use keyframes::KeyframesAnimation;
 use media_queries::Device;
 use parking_lot::RwLock;
+use pdqsort::sort_by;
 use properties::{self, CascadeFlags, ComputedValues, INHERIT_ALL, Importance};
 use properties::{PropertyDeclaration, PropertyDeclarationBlock};
-use quickersort::sort_by;
 use restyle_hints::{RestyleHint, DependencySet};
 use rule_tree::{RuleTree, StrongRuleNode, StyleSource};
 use selector_parser::{ElementExt, SelectorImpl, PseudoElement, Snapshot};
@@ -827,7 +827,7 @@ pub struct SelectorMap {
 
 #[inline]
 fn sort_by_key<T, F: Fn(&T) -> K, K: Ord>(v: &mut [T], f: F) {
-    sort_by(v, &|a, b| f(a).cmp(&f(b)))
+    sort_by(v, |a, b| f(a).cmp(&f(b)))
 }
 
 impl SelectorMap {