Auto merge of #16080 - mbrubeck:warnings, r=Wafflespeanut

Fix compiler warnings in stylo unit tests

- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] There are tests for these changes

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tests/unit/stylo/Cargo.toml

@@ -15,17 +15,14 @@ doctest = false
 testing = ["style/testing"]
 
 [dependencies]
-app_units = "0.4"
 atomic_refcell = "0.1"
 cssparser = "0.12"
 env_logger = "0.4"
 euclid = "0.11"
 lazy_static = "0.2"
 libc = "0.2"
 log = {version = "0.3.5", features = ["release_max_level_info"]}
-num_cpus = "1.1.0"
 parking_lot = "0.3"
-rayon = "0.6"
 selectors = {path = "../../../components/selectors"}
 servo_url = {path = "../../../components/url"}
 style_traits = {path = "../../../components/style_traits"}

tests/unit/stylo/lib.rs

@@ -2,17 +2,13 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-extern crate app_units;
 extern crate atomic_refcell;
 extern crate cssparser;
 extern crate env_logger;
-extern crate euclid;
 extern crate geckoservo;
 #[macro_use] extern crate lazy_static;
 #[macro_use] extern crate log;
-extern crate num_cpus;
 extern crate parking_lot;
-extern crate rayon;
 extern crate selectors;
 extern crate servo_url;
 #[macro_use] extern crate style;

tests/unit/stylo/sanity_checks.rs

@@ -31,8 +31,8 @@ macro_rules! check_enum_value_non_static {
 // similar, because we'd need the foreign atom symbols to link.
 #[test]
 fn assert_basic_pseudo_elements() {
-    let mut saw_before = false;
-    let mut saw_after = false;
+    let saw_before;
+    let saw_after;
 
     macro_rules! pseudo_element {
         (":before", $atom:expr, false) => {