Auto merge of #22133 - servo:extern-crate, r=SimonSapin

Use 2018-edition idioms in crates that use that edition

The first commit is almost entirely mechanical, created by running `cargo fix --edition-idioms` and relevant crates. I undid the change of adding an anonymous lifetime parameter in types that have implicit lifetimes parameters, for example replacing `&mut Formatter` with `&mut Formatter<'_>`, because I don’t like it. The remaining changes are, in many places:

* Add `dyn` to trait object types, for example `Rc<gl::Gl>` to `Rc<dyn gl::Gl>`. This change also works in the 2015 edition.
* Remove `extern crate` where is it made unneeded by changes to the import/module system.

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1 files changed, 7 insertions, 2 deletions

diff --git a/components/script/dom/workletglobalscope.rs b/components/script/dom/workletglobalscope.rs
index 9e672723c54..3d971390614 100644
--- a/components/script/dom/workletglobalscope.rs
+++ b/components/script/dom/workletglobalscope.rs
@@ -93,7 +93,12 @@ impl WorkletGlobalScope {
     }
 
     /// Register a paint worklet to the script thread.
-    pub fn register_paint_worklet(&self, name: Atom, properties: Vec<Atom>, painter: Box<Painter>) {
+    pub fn register_paint_worklet(
+        &self,
+        name: Atom,
+        properties: Vec<Atom>,
+        painter: Box<dyn Painter>,
+    ) {
         self.to_script_thread_sender
             .send(MainThreadScriptMsg::RegisterPaintWorklet {
                 pipeline_id: self.globalscope.pipeline_id(),
@@ -147,7 +152,7 @@ pub struct WorkletGlobalScopeInit {
     /// Message to send to the scheduler
     pub scheduler_chan: IpcSender<TimerSchedulerMsg>,
     /// The image cache
-    pub image_cache: Arc<ImageCache>,
+    pub image_cache: Arc<dyn ImageCache>,
 }
 
 /// <https://drafts.css-houdini.org/worklets/#worklet-global-scope-type>