Auto merge of #12392 - emilio:test-animations, r=SimonSapin

style: Add support to test animations programatically.

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---
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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 #12120

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- [x] There are tests for these changes OR

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r? @SimonSapin for the style changes, @Ms2ger or @jdm for the dom and test changes

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ports/cef/Cargo.lock

@@ -1045,7 +1045,6 @@ dependencies = [
  "string_cache 0.2.21 (registry+https://github.com/rust-lang/crates.io-index)",
  "style 0.0.1",
  "style_traits 0.0.1",
- "time 0.1.35 (registry+https://github.com/rust-lang/crates.io-index)",
  "unicode-bidi 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "unicode-script 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "url 1.1.1 (registry+https://github.com/rust-lang/crates.io-index)",

ports/geckolib/glue.rs

@@ -31,6 +31,7 @@ use style::properties::{ComputedValues, PropertyDeclarationBlock, parse_one_decl
 use style::selector_impl::{SelectorImplExt, PseudoElementCascadeType};
 use style::sequential;
 use style::stylesheets::{Stylesheet, Origin};
+use style::timer::Timer;
 use traversal::RecalcStyleOnly;
 use url::Url;
 use wrapper::{DUMMY_BASE_URL, GeckoDocument, GeckoElement, GeckoNode, NonOpaqueStyleData};
@@ -106,6 +107,7 @@ fn restyle_subtree(node: GeckoNode, raw_data: *mut RawServoStyleSet) {
         expired_animations: per_doc_data.expired_animations.clone(),
         error_reporter: Box::new(StdoutErrorReporter),
         local_context_creation_data: Mutex::new(local_context_data),
+        timer: Timer::new(),
     };
 
     if node.is_dirty() || node.has_dirty_descendants() {