Add webgpu feature flag (#34444)

* Move script gpu files into webgpu folder

Signed-off-by: atbrakhi <atbrakhi@igalia.com>

* Modify gpu webidls

Signed-off-by: atbrakhi <atbrakhi@igalia.com>

* move gpu realted webidl

Signed-off-by: atbrakhi <atbrakhi@igalia.com>

* add webgpu feature to script

Signed-off-by: atbrakhi <atbrakhi@igalia.com>

* add dummy implementation for gpucanvascontext

Signed-off-by: atbrakhi <atbrakhi@igalia.com>

* fmt

Signed-off-by: atbrakhi <atbrakhi@igalia.com>

* add skip-if CARGO_FEATURE_WEBGPU

Signed-off-by: atbrakhi <atbrakhi@igalia.com>

* Move NavigatorGPU and workerNavigator GPU to webgpu idl

Signed-off-by: atbrakhi <atbrakhi@igalia.com>

* fmt and cleanup

Signed-off-by: atbrakhi <atbrakhi@igalia.com>

* review fix

Signed-off-by: atbrakhi <atbrakhi@igalia.com>

* enable webgpu by default and also some fmt fix

Signed-off-by: atbrakhi <atbrakhi@igalia.com>

* Add pref back, fix imports, small cleanups

Signed-off-by: atbrakhi <atbrakhi@igalia.com>

---------

Signed-off-by: atbrakhi <atbrakhi@igalia.com>

components/script/dom/dissimilaroriginwindow.rs

@@ -64,6 +64,7 @@ impl DissimilarOriginWindow {
                 global_to_clone_from.microtask_queue().clone(),
                 global_to_clone_from.is_headless(),
                 global_to_clone_from.get_user_agent(),
+                #[cfg(feature = "webgpu")]
                 global_to_clone_from.wgpu_id_hub(),
                 Some(global_to_clone_from.is_secure_context()),
                 false,