Auto merge of #14232 - servo:moar-locks, r=upsuper

CSSOM: Make Stylesheet fields have their own synchronization

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r? @upsuper

---
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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 bug 1314208.

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

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ports/cef/Cargo.lock

@@ -1203,7 +1203,6 @@ dependencies = [
  "serde_json 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "servo_url 0.0.1",
  "style 0.0.1",
- "style_traits 0.0.1",
  "util 0.0.1",
  "webrender_traits 0.9.0 (git+https://github.com/servo/webrender)",
 ]

ports/geckolib/glue.rs

@@ -178,8 +178,8 @@ pub extern "C" fn Servo_StyleSheet_Empty(mode: SheetParsingMode) -> RawServoStyl
         SheetParsingMode::eUserSheetFeatures => Origin::User,
         SheetParsingMode::eAgentSheetFeatures => Origin::UserAgent,
     };
-    let sheet = Arc::new(Stylesheet::from_str("", url, origin, Box::new(StdoutErrorReporter),
-                                              extra_data));
+    let sheet = Arc::new(Stylesheet::from_str(
+        "", url, origin, Default::default(), Box::new(StdoutErrorReporter), extra_data));
     unsafe {
         transmute(sheet)
     }
@@ -208,8 +208,8 @@ pub extern "C" fn Servo_StyleSheet_FromUTF8Bytes(data: *const nsACString,
         referrer: Some(GeckoArcURI::new(referrer)),
         principal: Some(GeckoArcPrincipal::new(principal)),
     }};
-    let sheet = Arc::new(Stylesheet::from_str(input, url, origin, Box::new(StdoutErrorReporter),
-                                              extra_data));
+    let sheet = Arc::new(Stylesheet::from_str(
+        input, url, origin, Default::default(), Box::new(StdoutErrorReporter), extra_data));
     unsafe {
         transmute(sheet)
     }

ports/servo/Cargo.lock

@@ -1289,7 +1289,6 @@ dependencies = [
  "serde_json 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "servo_url 0.0.1",
  "style 0.0.1",
- "style_traits 0.0.1",
  "util 0.0.1",
  "webrender_traits 0.9.0 (git+https://github.com/servo/webrender)",
 ]