No tracing of nop traceable fields (#29926)

* Add `no_trace` option to JSTraceable derive

* NoTrace wrapper

* Port some types to no_trace schematics

* Fixing my unsafe mistakes (not tracing traceables)

* Add docs & safety guards for no_trace

Safety guards (trait shenanigans) guarantees safety usage of `no_trace`

* Port canvas_traits to no_trace

* Port servo_media to no_trace

* Port net_traits to no_trace

* Port style to no_trace

* Port webgpu to no_trace

* Port script_traits to no_trace

* Port canvas_traits, devtools_traits, embedder_traits, profile_traits to no_trace

* unrooted_must_root lint in seperate file

* Add trace_in_no_trace_lint as script_plugin

* Composable types in must_not_have_traceable

* Introduced HashMapTracedValues wrapper

* `HashMap<NoTrace<K>,V>`->`HashMapTracedValues<K,V>`

* Port rest of servo's types to no_trace

* Port html5ever, euclid, mime and http to no_trace

* Port remaining externals to no_trace

* Port webxr and Arc<Mutex<_>>

* Fix spelling in notrace doc

1 files changed, 4 insertions, 1 deletions

diff --git a/components/script/dom/cssstyledeclaration.rs b/components/script/dom/cssstyledeclaration.rs
index 41101afd625..a2cc459d94c 100644
--- a/components/script/dom/cssstyledeclaration.rs
+++ b/components/script/dom/cssstyledeclaration.rs
@@ -34,6 +34,7 @@ pub struct CSSStyleDeclaration {
     reflector_: Reflector,
     owner: CSSStyleOwner,
     readonly: bool,
+    #[no_trace]
     pseudo: Option<PseudoElement>,
 }
 
@@ -43,7 +44,9 @@ pub enum CSSStyleOwner {
     Element(Dom<Element>),
     CSSRule(
         Dom<CSSRule>,
-        #[ignore_malloc_size_of = "Arc"] Arc<Locked<PropertyDeclarationBlock>>,
+        #[ignore_malloc_size_of = "Arc"]
+        #[no_trace]
+        Arc<Locked<PropertyDeclarationBlock>>,
     ),
 }