Auto merge of #21881 - pyfisch:keyboard-types, r=paulrouget

Use keyboard-types crate

Have embedders send DOM keys to servo and use a strongly typed KeyboardEvent
from the W3C UI Events spec. All keyboard handling now uses the new types.

Introduce a ShortcutMatcher to recognize key bindings. Shortcuts are now
recognized in a uniform way.

Updated the winit port.
Updated webdriver integration.

part of #20331

What this PR does:

* allow the use non-ASCII keyboards for text input
* decouple keyboard event "key" from "code" (key meaning vs location)

What this PR does not do:

* completely improve keyboard events send from winit and webdriver
* add support for CompositionEvent or IME

Notes:

* The winit embedder does not send keyup events for printable keys (this is a regression)
* keyboard-types is on crates.io because I believe it to be useful outside of servo. If you prefer I can add a copy in this repo.

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components/malloc_size_of/lib.rs

@@ -52,6 +52,8 @@ extern crate hyper;
 #[cfg(feature = "servo")]
 extern crate hyper_serde;
 #[cfg(feature = "servo")]
+extern crate keyboard_types;
+#[cfg(feature = "servo")]
 extern crate mozjs as js;
 extern crate selectors;
 #[cfg(feature = "servo")]
@@ -955,6 +957,19 @@ malloc_size_of_is_0!(webrender_api::StickyOffsetBounds);
 #[cfg(feature = "webrender_api")]
 malloc_size_of_is_0!(webrender_api::TransformStyle);
 
+#[cfg(feature = "servo")]
+impl MallocSizeOf for keyboard_types::Key {
+    fn size_of(&self, ops: &mut MallocSizeOfOps) -> usize {
+        match self {
+            keyboard_types::Key::Character(ref s) => s.size_of(ops),
+            _ => 0,
+        }
+    }
+}
+
+#[cfg(feature = "servo")]
+malloc_size_of_is_0!(keyboard_types::Modifiers);
+
 #[cfg(feature = "servo")]
 impl MallocSizeOf for xml5ever::QualName {
     fn size_of(&self, ops: &mut MallocSizeOfOps) -> usize {