[WebDriver] Add synchronization for key action (#37403)

Implement action synchronization for key event. Previously only done for
pointer https://github.com/servo/servo/pull/36932 and wheel
https://github.com/servo/servo/pull/37260.

---------

Signed-off-by: PotatoCP <kenzieradityatirtarahardja18@gmail.com>

components/shared/embedder/input_events.rs

@@ -2,7 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
-use keyboard_types::{CompositionEvent, KeyboardEvent};
+use keyboard_types::{Code, CompositionEvent, Key, KeyState, Location, Modifiers};
 use log::error;
 use malloc_size_of_derive::MallocSizeOf;
 use serde::{Deserialize, Serialize};
@@ -53,7 +53,7 @@ impl InputEvent {
             InputEvent::EditingAction(..) => None,
             InputEvent::Gamepad(..) => None,
             InputEvent::Ime(..) => None,
-            InputEvent::Keyboard(..) => None,
+            InputEvent::Keyboard(event) => event.webdriver_id,
             InputEvent::MouseButton(event) => event.webdriver_id,
             InputEvent::MouseMove(event) => event.webdriver_id,
             InputEvent::Touch(..) => None,
@@ -67,7 +67,9 @@ impl InputEvent {
             InputEvent::EditingAction(..) => {},
             InputEvent::Gamepad(..) => {},
             InputEvent::Ime(..) => {},
-            InputEvent::Keyboard(..) => {},
+            InputEvent::Keyboard(ref mut event) => {
+                event.webdriver_id = webdriver_id;
+            },
             InputEvent::MouseButton(ref mut event) => {
                 event.webdriver_id = webdriver_id;
             },
@@ -85,6 +87,51 @@ impl InputEvent {
     }
 }
 
+/// Recreate KeyboardEvent from keyboard_types to pair it with webdriver_id,
+/// which is used for webdriver action synchronization.
+#[derive(Clone, Debug, Default, Deserialize, Serialize)]
+pub struct KeyboardEvent {
+    pub event: ::keyboard_types::KeyboardEvent,
+    webdriver_id: Option<WebDriverMessageId>,
+}
+
+impl KeyboardEvent {
+    pub fn new(keyboard_event: ::keyboard_types::KeyboardEvent) -> Self {
+        Self {
+            event: keyboard_event,
+            webdriver_id: None,
+        }
+    }
+
+    pub fn new_without_event(
+        state: KeyState,
+        key: Key,
+        code: Code,
+        location: Location,
+        modifiers: Modifiers,
+        repeat: bool,
+        is_composing: bool,
+    ) -> Self {
+        Self::new(::keyboard_types::KeyboardEvent {
+            state,
+            key,
+            code,
+            location,
+            modifiers,
+            repeat,
+            is_composing,
+        })
+    }
+
+    pub fn from_state_and_key(state: KeyState, key: Key) -> Self {
+        Self::new(::keyboard_types::KeyboardEvent {
+            state,
+            key,
+            ..::keyboard_types::KeyboardEvent::default()
+        })
+    }
+}
+
 #[derive(Clone, Copy, Debug, Deserialize, Serialize)]
 pub struct MouseButtonEvent {
     pub action: MouseButtonAction,