Add OpenHarmony support to servoshell (#32594)

* Generate EGL bindings for ohos

Signed-off-by: Jonathan Schwender <jonathan.schwender@huawei.com>

* Adjust servoshell `bin` error message for android/ohos

Signed-off-by: Jonathan Schwender <jonathan.schwender@huawei.com>

* ohos: disable WebGL

offscreen buffers are not implemented yet on ohos.

Signed-off-by: Jonathan Schwender <jonathan.schwender@huawei.com>

* Add OpenHarmony support to servoshell

Signed-off-by: Jonathan Schwender <jonathan.schwender@huawei.com>

* Share ResourceReaderInstance

Signed-off-by: Jonathan Schwender <jonathan.schwender@huawei.com>

* Share android/ohos HostTrait

Signed-off-by: Jonathan Schwender <jonathan.schwender@huawei.com>

* Share servo glue

Signed-off-by: Jonathan Schwender <jonathan.schwender@huawei.com>
Signed-off-by: Jonathan Schwender <schwenderjonathan@gmail.com>

* Pass Init options from ArkTS to Servo

Signed-off-by: Jonathan Schwender <jonathan.schwender@huawei.com>

* f rebase ResourceReaderMethods

Signed-off-by: Jonathan Schwender <jonathan.schwender@huawei.com>

* fixup! Share ResourceReaderInstance

Signed-off-by: Jonathan Schwender <jonathan.schwender@huawei.com>

* Fix typo

Signed-off-by: Jonathan Schwender <jonathan.schwender@huawei.com>

* Update Cargo.lock

Signed-off-by: Jonathan Schwender <jonathan.schwender@huawei.com>

* ohos: Move WebGL check to webgl thread

Signed-off-by: Jonathan Schwender <jonathan.schwender@huawei.com>

* Remove commented code

Signed-off-by: Jonathan Schwender <jonathan.schwender@huawei.com>

* Remove commented and duplicate / unused code

Signed-off-by: Jonathan Schwender <jonathan.schwender@huawei.com>

---------

Signed-off-by: Jonathan Schwender <jonathan.schwender@huawei.com>
Signed-off-by: Jonathan Schwender <schwenderjonathan@gmail.com>

ports/servoshell/egl/host_trait.rs

@@ -0,0 +1,75 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * 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 servo::embedder_traits::{InputMethodType, MediaSessionPlaybackState, PromptResult};
+use servo::webrender_api::units::DeviceIntRect;
+
+/// Callbacks. Implemented by embedder. Called by Servo.
+pub trait HostTrait {
+    /// Show alert.
+    fn prompt_alert(&self, msg: String, trusted: bool);
+    /// Ask Yes/No question.
+    fn prompt_yes_no(&self, msg: String, trusted: bool) -> PromptResult;
+    /// Ask Ok/Cancel question.
+    fn prompt_ok_cancel(&self, msg: String, trusted: bool) -> PromptResult;
+    /// Ask for string
+    fn prompt_input(&self, msg: String, default: String, trusted: bool) -> Option<String>;
+    /// Show context menu
+    fn show_context_menu(&self, title: Option<String>, items: Vec<String>);
+    /// Page starts loading.
+    /// "Reload button" should be disabled.
+    /// "Stop button" should be enabled.
+    /// Throbber starts spinning.
+    fn on_load_started(&self);
+    /// Page has loaded.
+    /// "Reload button" should be enabled.
+    /// "Stop button" should be disabled.
+    /// Throbber stops spinning.
+    fn on_load_ended(&self);
+    /// Page title has changed.
+    fn on_title_changed(&self, title: Option<String>);
+    /// Allow Navigation.
+    fn on_allow_navigation(&self, url: String) -> bool;
+    /// Page URL has changed.
+    fn on_url_changed(&self, url: String);
+    /// Back/forward state has changed.
+    /// Back/forward buttons need to be disabled/enabled.
+    fn on_history_changed(&self, can_go_back: bool, can_go_forward: bool);
+    /// Page animation state has changed. If animating, it's recommended
+    /// that the embedder doesn't wait for the wake function to be called
+    /// to call perform_updates. Usually, it means doing:
+    /// while true { servo.perform_updates() }. This will end up calling flush
+    /// which will call swap_buffer which will be blocking long enough to limit
+    /// drawing at 60 FPS.
+    /// If not animating, call perform_updates only when needed (when the embedder
+    /// has events for Servo, or Servo has woken up the embedder event loop via
+    /// EventLoopWaker).
+    fn on_animating_changed(&self, animating: bool);
+    /// Servo finished shutting down.
+    fn on_shutdown_complete(&self);
+    /// A text input is focused.
+    fn on_ime_show(
+        &self,
+        input_type: InputMethodType,
+        text: Option<(String, i32)>,
+        multiline: bool,
+        bounds: DeviceIntRect,
+    );
+    /// Input lost focus
+    fn on_ime_hide(&self);
+    /// Gets sytem clipboard contents.
+    fn get_clipboard_contents(&self) -> Option<String>;
+    /// Sets system clipboard contents.
+    fn set_clipboard_contents(&self, contents: String);
+    /// Called when we get the media session metadata/
+    fn on_media_session_metadata(&self, title: String, artist: String, album: String);
+    /// Called when the media session playback state changes.
+    fn on_media_session_playback_state_change(&self, state: MediaSessionPlaybackState);
+    /// Called when the media session position state is set.
+    fn on_media_session_set_position_state(&self, duration: f64, position: f64, playback_rate: f64);
+    /// Called when devtools server is started
+    fn on_devtools_started(&self, port: Result<u16, ()>, token: String);
+    /// Called when we get a panic message from constellation
+    fn on_panic(&self, reason: String, backtrace: Option<String>);
+}