constellation: Eliminate long-standing inactive code path for WebDriverData (#38221)

Cleaning up some dead code which has been here for 9 years. They are
never detected by Lint because we still initialize them as `None` but
never change afterwards.

Testing: No regression.

---------

Signed-off-by: Euclid Ye <euclid.ye@huawei.com>
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Martin Robinson <mrobinson@igalia.com>

Cargo.lock

@@ -1467,7 +1467,6 @@ dependencies = [
  "servo_config",
  "servo_rand",
  "servo_url",
- "stylo_traits",
  "tracing",
  "webgpu",
  "webgpu_traits",

components/constellation/Cargo.toml

@@ -47,7 +47,6 @@ serde = { workspace = true }
 servo_config = { path = "../config" }
 servo_rand = { path = "../rand" }
 servo_url = { path = "../url" }
-stylo_traits = { workspace = true }
 tracing = { workspace = true, optional = true }
 webgpu = { path = "../webgpu" }
 webgpu_traits = { workspace = true }

components/constellation/constellation.rs

@@ -133,7 +133,7 @@ use embedder_traits::{
     FocusSequenceNumber, InputEvent, JSValue, JavaScriptEvaluationError, JavaScriptEvaluationId,
     KeyboardEvent, MediaSessionActionType, MediaSessionEvent, MediaSessionPlaybackState,
     MouseButton, MouseButtonAction, MouseButtonEvent, Theme, ViewportDetails, WebDriverCommandMsg,
-    WebDriverCommandResponse, WebDriverLoadStatus,
+    WebDriverCommandResponse,
 };
 use euclid::Size2D;
 use euclid::default::Size2D as UntypedSize2D;
@@ -159,7 +159,6 @@ use serde::{Deserialize, Serialize};
 use servo_config::{opts, pref};
 use servo_rand::{Rng, ServoRng, SliceRandom, random};
 use servo_url::{Host, ImmutableOrigin, ServoUrl};
-use style_traits::CSSPixel;
 #[cfg(feature = "webgpu")]
 use webgpu::swapchain::WGPUImageMap;
 #[cfg(feature = "webgpu")]
@@ -397,8 +396,8 @@ pub struct Constellation<STF, SWF> {
     /// and the namespaces are allocated by the constellation.
     next_pipeline_namespace_id: PipelineNamespaceId,
 
-    /// Bits of state used to interact with the webdriver implementation
-    webdriver: WebDriverData,
+    /// An [`IpcSender`] to forward responses from the `ScriptThread` to the WebDriver server.
+    webdriver_input_command_reponse_sender: Option<IpcSender<WebDriverCommandResponse>>,
 
     /// Document states for loaded pipelines (used only when writing screenshots).
     document_states: HashMap<PipelineId, DocumentState>,
@@ -506,24 +505,6 @@ pub struct InitialConstellationState {
     pub user_content_manager: UserContentManager,
 }
 
-/// Data needed for webdriver
-struct WebDriverData {
-    load_channel: Option<(PipelineId, IpcSender<WebDriverLoadStatus>)>,
-    resize_channel: Option<IpcSender<Size2D<f32, CSSPixel>>>,
-    // Forward responses from the script thread to the webdriver server.
-    input_command_response_sender: Option<IpcSender<WebDriverCommandResponse>>,
-}
-
-impl WebDriverData {
-    fn new() -> WebDriverData {
-        WebDriverData {
-            load_channel: None,
-            resize_channel: None,
-            input_command_response_sender: None,
-        }
-    }
-}
-
 /// When we are running reftests, we save an image to compare against a reference.
 /// This enum gives the possible states of preparing such an image.
 #[derive(Debug, PartialEq)]
@@ -685,7 +666,7 @@ where
                     time_profiler_chan: state.time_profiler_chan,
                     mem_profiler_chan: state.mem_profiler_chan.clone(),
                     phantom: PhantomData,
-                    webdriver: WebDriverData::new(),
+                    webdriver_input_command_reponse_sender: None,
                     document_states: HashMap::new(),
                     #[cfg(feature = "webgpu")]
                     webrender_wgpu,
@@ -1352,7 +1333,7 @@ where
             // Create a new top level browsing context. Will use response_chan to return
             // the browsing context id.
             EmbedderToConstellationMessage::NewWebView(url, webview_id, viewport_details) => {
-                self.handle_new_top_level_browsing_context(url, webview_id, viewport_details, None);
+                self.handle_new_top_level_browsing_context(url, webview_id, viewport_details);
             },
             // Close a top level browsing context.
             EmbedderToConstellationMessage::CloseWebView(webview_id) => {
@@ -1473,7 +1454,7 @@ where
                 }
             },
             EmbedderToConstellationMessage::SetWebDriverResponseSender(sender) => {
-                self.webdriver.input_command_response_sender = Some(sender);
+                self.webdriver_input_command_reponse_sender = Some(sender);
             },
         }
     }
@@ -1874,14 +1855,14 @@ where
                 self.handle_finish_javascript_evaluation(evaluation_id, result)
             },
             ScriptToConstellationMessage::WebDriverInputComplete(msg_id) => {
-                if let Some(ref reply_sender) = self.webdriver.input_command_response_sender {
+                if let Some(ref reply_sender) = self.webdriver_input_command_reponse_sender {
                     reply_sender
                         .send(WebDriverCommandResponse { id: msg_id })
                         .unwrap_or_else(|_| {
                             warn!("Failed to send WebDriverInputComplete {:?}", msg_id);
                         });
                 } else {
-                    warn!("No WebDriver input_command_response_sender");
+                    warn!("No webdriver_input_command_reponse_sender");
                 }
             },
         }
@@ -2945,7 +2926,6 @@ where
         url: ServoUrl,
         webview_id: WebViewId,
         viewport_details: ViewportDetails,
-        response_sender: Option<IpcSender<WebDriverLoadStatus>>,
     ) {
         let pipeline_id = PipelineId::new();
         let browsing_context_id = BrowsingContextId::from(webview_id);
@@ -3002,10 +2982,6 @@ where
             }),
             viewport_details,
         });
-
-        if let Some(response_sender) = response_sender {
-            self.webdriver.load_channel = Some((pipeline_id, response_sender));
-        }
     }
 
     #[servo_tracing::instrument(skip_all)]
@@ -3628,18 +3604,6 @@ where
 
     #[servo_tracing::instrument(skip_all)]
     fn handle_load_complete_msg(&mut self, webview_id: WebViewId, pipeline_id: PipelineId) {
-        let mut webdriver_reset = false;
-        if let Some((expected_pipeline_id, ref reply_chan)) = self.webdriver.load_channel {
-            if expected_pipeline_id == pipeline_id {
-                debug!("Sending load for {:?} to WebDriver", expected_pipeline_id);
-                let _ = reply_chan.send(WebDriverLoadStatus::Complete);
-                webdriver_reset = true;
-            }
-        }
-        if webdriver_reset {
-            self.webdriver.load_channel = None;
-        }
-
         if let Some(pipeline) = self.pipelines.get_mut(&pipeline_id) {
             debug!("{}: Marking as loaded", pipeline_id);
             pipeline.completely_loaded = true;
@@ -4930,10 +4894,6 @@ where
 
         let browsing_context_id = BrowsingContextId::from(webview_id);
         self.resize_browsing_context(new_viewport_details, size_type, browsing_context_id);
-
-        if let Some(response_sender) = self.webdriver.resize_channel.take() {
-            let _ = response_sender.send(new_viewport_details.size);
-        }
     }
 
     /// Called when the window exits from fullscreen mode

components/script/webdriver_handlers.rs

@@ -1103,8 +1103,10 @@ fn handle_send_keys_file(
     Ok(false)
 }
 
-/// Implementing step 5 - 8 of Element Send Keys. This function will send a boolean
-/// back to webdriver_server, indicating whether the dispatching of the key and
+/// Implementing step 5 - 7, plus part of step 8 of "Element Send Keys"
+/// where element is input element in the file upload state.
+/// This function will send a boolean back to webdriver_server,
+/// indicating whether the dispatching of the key and
 /// composition event is still needed or not.
 pub(crate) fn handle_will_send_keys(
     documents: &DocumentCollection,

components/shared/embedder/webdriver.rs

@@ -243,7 +243,7 @@ pub enum WebDriverScriptCommand {
     IsEnabled(String, IpcSender<Result<bool, ErrorStatus>>),
     IsSelected(String, IpcSender<Result<bool, ErrorStatus>>),
     GetTitle(IpcSender<String>),
-    /// Match the element type before sending the event for webdriver `element send keys`.
+    /// Deal with the case of input element for Element Send Keys, which does not send keys.
     WillSendKeys(String, String, bool, IpcSender<Result<bool, ErrorStatus>>),
     IsDocumentReadyStateComplete(IpcSender<bool>),
 }