Implement WebResourceRequested Event. (#34961)

* Implement WebResourceRequested Event on the Embedder Layer

Signed-off-by: zhuhaichao518 <zhuhaichao518@gmail.com>

* fix and add test

Signed-off-by: zhuhaichao518 <zhuhaichao518@gmail.com>

* resolve comments

Signed-off-by: zhuhaichao518 <zhuhaichao518@gmail.com>

* remove sample code in webview

Signed-off-by: zhuhaichao518 <zhuhaichao518@gmail.com>

* remove typo

Signed-off-by: zhuhaichao518 <zhuhaichao518@gmail.com>

* ./mach format

Signed-off-by: zhuhaichao518 <zhuhaichao518@gmail.com>

* fix test fail caused by interception message

Signed-off-by: zhuhaichao518 <zhuhaichao518@gmail.com>

* update impl for is_for_main_frame

Signed-off-by: zhuhaichao518 <zhuhaichao518@gmail.com>

---------

Signed-off-by: zhuhaichao518 <zhuhaichao518@gmail.com>

Cargo.lock

@@ -1746,12 +1746,16 @@ dependencies = [
  "base",
  "cfg-if",
  "crossbeam-channel",
+ "http 1.2.0",
+ "hyper_serde",
  "ipc-channel",
  "keyboard-types",
  "log",
+ "malloc_size_of_derive",
  "num-derive",
  "num-traits",
  "serde",
+ "servo_malloc_size_of",
  "servo_url",
  "webrender_api",
  "webxr-api",

components/constellation/tracing.rs

@@ -215,6 +215,7 @@ mod from_script {
                 Self::WebViewClosed(..) => target_variant!("WebViewClosed"),
                 Self::WebViewFocused(..) => target_variant!("WebViewFocused"),
                 Self::WebViewBlurred => target_variant!("WebViewBlurred"),
+                Self::WebResourceRequested(..) => target_variant!("WebResourceRequested"),
                 Self::AllowUnload(..) => target_variant!("AllowUnload"),
                 Self::Keyboard(..) => target_variant!("Keyboard"),
                 Self::ClearClipboardContents => target_variant!("ClearClipboardContents"),

components/net/fetch/methods.rs

@@ -43,6 +43,7 @@ use crate::fetch::headers::determine_nosniff;
 use crate::filemanager_thread::FileManager;
 use crate::http_loader::{determine_requests_referrer, http_fetch, set_default_accept, HttpState};
 use crate::protocols::ProtocolRegistry;
+use crate::request_intercepter::RequestIntercepter;
 use crate::subresource_integrity::is_response_integrity_valid;
 
 pub type Target<'a> = &'a mut (dyn FetchTaskTarget + Send);
@@ -60,6 +61,7 @@ pub struct FetchContext {
     pub devtools_chan: Option<Arc<Mutex<Sender<DevtoolsControlMsg>>>>,
     pub filemanager: Arc<Mutex<FileManager>>,
     pub file_token: FileTokenCheck,
+    pub request_intercepter: Arc<Mutex<RequestIntercepter>>,
     pub cancellation_listener: Arc<CancellationListener>,
     pub timing: ServoArc<Mutex<ResourceFetchTiming>>,
     pub protocols: Arc<ProtocolRegistry>,
@@ -193,6 +195,18 @@ pub fn should_request_be_blocked_by_csp(
         .unwrap_or(csp::CheckResult::Allowed)
 }
 
+pub fn maybe_intercept_request(
+    request: &mut Request,
+    context: &FetchContext,
+    response: &mut Option<Response>,
+) {
+    context
+        .request_intercepter
+        .lock()
+        .unwrap()
+        .intercept_request(request, response, context);
+}
+
 /// [Main fetch](https://fetch.spec.whatwg.org/#concept-main-fetch)
 pub async fn main_fetch(
     fetch_params: &mut FetchParams,
@@ -299,6 +313,9 @@ pub async fn main_fetch(
     let current_url = request.current_url();
     let current_scheme = current_url.scheme();
 
+    // Intercept the request and maybe override the response.
+    maybe_intercept_request(request, context, &mut response);
+
     let mut response = match response {
         Some(res) => res,
         None => {

components/net/lib.rs

@@ -18,6 +18,7 @@ pub mod image_cache;
 pub mod local_directory_listing;
 pub mod mime_classifier;
 pub mod protocols;
+pub mod request_intercepter;
 pub mod resource_thread;
 mod storage_thread;
 pub mod subresource_integrity;

components/net/request_intercepter.rs

@@ -0,0 +1,104 @@
+/* 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 content_security_policy::Destination;
+use embedder_traits::{
+    EmbedderMsg, EmbedderProxy, HttpBodyData, WebResourceRequest, WebResourceResponseMsg,
+};
+use ipc_channel::ipc;
+use net_traits::http_status::HttpStatus;
+use net_traits::request::Request;
+use net_traits::response::{Response, ResponseBody};
+use net_traits::NetworkError;
+
+use crate::fetch::methods::FetchContext;
+
+#[derive(Clone)]
+pub struct RequestIntercepter {
+    embedder_proxy: EmbedderProxy,
+}
+
+impl RequestIntercepter {
+    pub fn new(embedder_proxy: EmbedderProxy) -> RequestIntercepter {
+        RequestIntercepter { embedder_proxy }
+    }
+
+    pub fn intercept_request(
+        &self,
+        request: &mut Request,
+        response: &mut Option<Response>,
+        context: &FetchContext,
+    ) {
+        let (tx, rx) = ipc::channel().unwrap();
+        let is_for_main_frame = matches!(request.destination, Destination::Document);
+        let req = WebResourceRequest::new(
+            request.method.clone(),
+            request.headers.clone(),
+            request.url(),
+            is_for_main_frame,
+            request.redirect_count > 0,
+        );
+
+        self.embedder_proxy.send((
+            request.target_browsing_context_id,
+            EmbedderMsg::WebResourceRequested(req, tx),
+        ));
+        let mut response_received = false;
+
+        // TODO: use done_chan and run in CoreResourceThreadPool.
+        while let Ok(msg) = rx.recv() {
+            match msg {
+                WebResourceResponseMsg::Start(webresource_response) => {
+                    response_received = true;
+                    let timing = context.timing.lock().unwrap().clone();
+                    let mut res = Response::new(webresource_response.url.clone(), timing);
+                    res.headers = webresource_response.headers;
+                    res.status = HttpStatus::new(
+                        webresource_response.status_code,
+                        webresource_response.status_message,
+                    );
+                    *res.body.lock().unwrap() = ResponseBody::Receiving(Vec::new());
+                    *response = Some(res);
+                },
+                WebResourceResponseMsg::Body(data) => {
+                    if !response_received {
+                        panic!("Receive body before initializing a Response!");
+                    }
+                    if let Some(ref mut res) = *response {
+                        match data {
+                            HttpBodyData::Chunk(chunk) => {
+                                if let ResponseBody::Receiving(ref mut body) =
+                                    *res.body.lock().unwrap()
+                                {
+                                    body.extend_from_slice(&chunk);
+                                } else {
+                                    panic!("Receive Playload Message when Response body is not in Receiving state!");
+                                }
+                            },
+                            HttpBodyData::Done => {
+                                let mut res_body = res.body.lock().unwrap();
+                                if let ResponseBody::Receiving(ref mut body) = *res_body {
+                                    let completed_body = std::mem::take(body);
+                                    *res_body = ResponseBody::Done(completed_body);
+                                } else {
+                                    panic!("Receive Done Message when Response body is not in Receiving state!");
+                                }
+                                break;
+                            },
+                            HttpBodyData::Cancelled => {
+                                *response =
+                                    Some(Response::network_error(NetworkError::LoadCancelled));
+                                break;
+                            },
+                        }
+                    }
+                },
+                WebResourceResponseMsg::None => {
+                    // Will not intercept the response. Continue.
+                    break;
+                },
+            }
+        }
+    }
+}

components/net/resource_thread.rs

@@ -54,6 +54,7 @@ use crate::hsts::HstsList;
 use crate::http_cache::HttpCache;
 use crate::http_loader::{http_redirect_fetch, HttpState};
 use crate::protocols::ProtocolRegistry;
+use crate::request_intercepter::RequestIntercepter;
 use crate::storage_thread::StorageThreadFactory;
 use crate::websocket_loader;
 
@@ -552,6 +553,7 @@ pub struct CoreResourceManager {
     devtools_sender: Option<Sender<DevtoolsControlMsg>>,
     sw_managers: HashMap<ImmutableOrigin, IpcSender<CustomResponseMediator>>,
     filemanager: FileManager,
+    request_intercepter: RequestIntercepter,
     thread_pool: Arc<CoreResourceThreadPool>,
     ca_certificates: CACertificates,
     ignore_certificate_errors: bool,
@@ -703,7 +705,8 @@ impl CoreResourceManager {
             user_agent,
             devtools_sender,
             sw_managers: Default::default(),
-            filemanager: FileManager::new(embedder_proxy, Arc::downgrade(&pool_handle)),
+            filemanager: FileManager::new(embedder_proxy.clone(), Arc::downgrade(&pool_handle)),
+            request_intercepter: RequestIntercepter::new(embedder_proxy),
             thread_pool: pool_handle,
             ca_certificates,
             ignore_certificate_errors,
@@ -746,6 +749,7 @@ impl CoreResourceManager {
         let ua = self.user_agent.clone();
         let dc = self.devtools_sender.clone();
         let filemanager = self.filemanager.clone();
+        let request_intercepter = self.request_intercepter.clone();
 
         let timing_type = match request_builder.destination {
             Destination::Document => ResourceTimingType::Navigation,
@@ -787,6 +791,7 @@ impl CoreResourceManager {
                 devtools_chan: dc.map(|dc| Arc::new(Mutex::new(dc))),
                 filemanager: Arc::new(Mutex::new(filemanager)),
                 file_token,
+                request_intercepter: Arc::new(Mutex::new(request_intercepter)),
                 cancellation_listener,
                 timing: ServoArc::new(Mutex::new(ResourceFetchTiming::new(request.timing_type()))),
                 protocols,

components/net/tests/fetch.rs

@@ -30,6 +30,7 @@ use net::fetch::methods::{self, FetchContext};
 use net::filemanager_thread::FileManager;
 use net::hsts::HstsEntry;
 use net::protocols::ProtocolRegistry;
+use net::request_intercepter::RequestIntercepter;
 use net::resource_thread::CoreResourceThreadPool;
 use net_traits::filemanager_thread::FileTokenCheck;
 use net_traits::http_status::HttpStatus;
@@ -47,8 +48,9 @@ use uuid::Uuid;
 
 use crate::http_loader::{expect_devtools_http_request, expect_devtools_http_response};
 use crate::{
-    create_embedder_proxy, create_http_state, fetch, fetch_with_context, fetch_with_cors_cache,
-    make_body, make_server, make_ssl_server, new_fetch_context, DEFAULT_USER_AGENT,
+    create_embedder_proxy, create_embedder_proxy_and_receiver, create_http_state, fetch,
+    fetch_with_context, fetch_with_cors_cache, make_body, make_server, make_ssl_server,
+    new_fetch_context, DEFAULT_USER_AGENT,
 };
 
 // TODO write a struct that impls Handler for storing test values
@@ -695,15 +697,18 @@ fn test_fetch_with_hsts() {
 
     let (server, url) = make_ssl_server(handler);
 
+    let embedder_proxy = create_embedder_proxy();
+
     let mut context = FetchContext {
         state: Arc::new(create_http_state(None)),
         user_agent: DEFAULT_USER_AGENT.into(),
         devtools_chan: None,
         filemanager: Arc::new(Mutex::new(FileManager::new(
-            create_embedder_proxy(),
+            embedder_proxy.clone(),
             Weak::new(),
         ))),
         file_token: FileTokenCheck::NotRequired,
+        request_intercepter: Arc::new(Mutex::new(RequestIntercepter::new(embedder_proxy))),
         cancellation_listener: Arc::new(Default::default()),
         timing: ServoArc::new(Mutex::new(ResourceFetchTiming::new(
             ResourceTimingType::Navigation,
@@ -752,15 +757,18 @@ fn test_load_adds_host_to_hsts_list_when_url_is_https() {
     let (server, mut url) = make_ssl_server(handler);
     url.as_mut_url().set_scheme("https").unwrap();
 
+    let embedder_proxy = create_embedder_proxy();
+
     let mut context = FetchContext {
         state: Arc::new(create_http_state(None)),
         user_agent: DEFAULT_USER_AGENT.into(),
         devtools_chan: None,
         filemanager: Arc::new(Mutex::new(FileManager::new(
-            create_embedder_proxy(),
+            embedder_proxy.clone(),
             Weak::new(),
         ))),
         file_token: FileTokenCheck::NotRequired,
+        request_intercepter: Arc::new(Mutex::new(RequestIntercepter::new(embedder_proxy))),
         cancellation_listener: Arc::new(Default::default()),
         timing: ServoArc::new(Mutex::new(ResourceFetchTiming::new(
             ResourceTimingType::Navigation,
@@ -811,15 +819,18 @@ fn test_fetch_self_signed() {
     let (server, mut url) = make_ssl_server(handler);
     url.as_mut_url().set_scheme("https").unwrap();
 
+    let embedder_proxy = create_embedder_proxy();
+
     let mut context = FetchContext {
         state: Arc::new(create_http_state(None)),
         user_agent: DEFAULT_USER_AGENT.into(),
         devtools_chan: None,
         filemanager: Arc::new(Mutex::new(FileManager::new(
-            create_embedder_proxy(),
+            embedder_proxy.clone(),
             Weak::new(),
         ))),
         file_token: FileTokenCheck::NotRequired,
+        request_intercepter: Arc::new(Mutex::new(RequestIntercepter::new(embedder_proxy))),
         cancellation_listener: Arc::new(Default::default()),
         timing: ServoArc::new(Mutex::new(ResourceFetchTiming::new(
             ResourceTimingType::Navigation,
@@ -1320,3 +1331,102 @@ fn test_fetch_with_devtools() {
     assert_eq!(devhttprequest, httprequest);
     assert_eq!(devhttpresponse, httpresponse);
 }
+
+#[test]
+fn test_fetch_request_intercepted() {
+    static BODY_PART1: &[u8] = b"Request is";
+    static BODY_PART2: &[u8] = b" intercepted";
+    static EXPECTED_BODY: &[u8] = b"Request is intercepted";
+    static HEADERNAME: &str = "custom-header";
+    static HEADERVALUE: &str = "custom-value";
+    static STATUS_MESSAGE: &[u8] = b"custom status message";
+
+    let (embedder_proxy, mut embedder_receiver) = create_embedder_proxy_and_receiver();
+
+    std::thread::spawn(move || {
+        let (_browser_context_id, embedder_msg) = embedder_receiver.recv_embedder_msg();
+        match embedder_msg {
+            embedder_traits::EmbedderMsg::WebResourceRequested(
+                web_resource_request,
+                response_sender,
+            ) => {
+                let mut headers = HeaderMap::new();
+                headers.insert(
+                    HeaderName::from_static(HEADERNAME),
+                    HeaderValue::from_static(HEADERVALUE),
+                );
+                let response =
+                    embedder_traits::WebResourceResponse::new(web_resource_request.url.clone())
+                        .headers(headers)
+                        .status_code(StatusCode::FOUND)
+                        .status_message(STATUS_MESSAGE.to_vec());
+                let msg = embedder_traits::WebResourceResponseMsg::Start(response);
+                let _ = response_sender.send(msg);
+                let msg2 = embedder_traits::WebResourceResponseMsg::Body(
+                    embedder_traits::HttpBodyData::Chunk(BODY_PART1.to_vec()),
+                );
+                let _ = response_sender.send(msg2);
+                let msg3 = embedder_traits::WebResourceResponseMsg::Body(
+                    embedder_traits::HttpBodyData::Chunk(BODY_PART2.to_vec()),
+                );
+                let _ = response_sender.send(msg3);
+                let _ = response_sender.send(embedder_traits::WebResourceResponseMsg::Body(
+                    embedder_traits::HttpBodyData::Done,
+                ));
+            },
+            _ => unreachable!(),
+        }
+    });
+
+    let mut context = FetchContext {
+        state: Arc::new(create_http_state(None)),
+        user_agent: DEFAULT_USER_AGENT.into(),
+        devtools_chan: None,
+        filemanager: Arc::new(Mutex::new(FileManager::new(
+            embedder_proxy.clone(),
+            Weak::new(),
+        ))),
+        file_token: FileTokenCheck::NotRequired,
+        request_intercepter: Arc::new(Mutex::new(RequestIntercepter::new(embedder_proxy))),
+        cancellation_listener: Arc::new(Default::default()),
+        timing: ServoArc::new(Mutex::new(ResourceFetchTiming::new(
+            ResourceTimingType::Navigation,
+        ))),
+        protocols: Arc::new(ProtocolRegistry::default()),
+    };
+
+    let url = ServoUrl::parse("http://www.example.org").unwrap();
+    let request = RequestBuilder::new(url.clone(), Referrer::NoReferrer)
+        .origin(url.origin())
+        .build();
+    let response = fetch_with_context(request, &mut context);
+
+    assert!(
+        response
+            .headers
+            .get(HEADERNAME)
+            .map(|v| v == HEADERVALUE)
+            .unwrap_or(false),
+        "The custom header does not exist or has an incorrect value!"
+    );
+
+    let body = response.body.lock().unwrap();
+    match &*body {
+        ResponseBody::Done(data) => {
+            assert_eq!(data, &EXPECTED_BODY, "Body content does not match");
+        },
+        _ => panic!("Expected ResponseBody::Done, but got {:?}", *body),
+    }
+
+    assert_eq!(
+        response.status.code(),
+        StatusCode::FOUND,
+        "Status code does not match!"
+    );
+
+    assert_eq!(
+        response.status.message(),
+        STATUS_MESSAGE,
+        "The status_message was not set correctly!"
+    );
+}

components/net/tests/main.rs

@@ -42,6 +42,7 @@ use net::fetch::cors_cache::CorsCache;
 use net::fetch::methods::{self, FetchContext};
 use net::filemanager_thread::FileManager;
 use net::protocols::ProtocolRegistry;
+use net::request_intercepter::RequestIntercepter;
 use net::resource_thread::CoreResourceThreadPool;
 use net::test::HttpState;
 use net_traits::filemanager_thread::FileTokenCheck;
@@ -128,7 +129,7 @@ fn receive_credential_prompt_msgs(
     username: Option<String>,
     password: Option<String>,
 ) -> std::thread::JoinHandle<()> {
-    std::thread::spawn(move || {
+    std::thread::spawn(move || loop {
         let (_browser_context_id, embedder_msg) = embedder_receiver.recv_embedder_msg();
         match embedder_msg {
             embedder_traits::EmbedderMsg::Prompt(prompt_definition, _prompt_origin) => {
@@ -140,7 +141,9 @@ fn receive_credential_prompt_msgs(
                     },
                     _ => unreachable!(),
                 }
+                break;
             },
+            embedder_traits::EmbedderMsg::WebResourceRequested(_, _) => {},
             _ => unreachable!(),
         }
     })
@@ -179,10 +182,11 @@ fn new_fetch_context(
         user_agent: DEFAULT_USER_AGENT.into(),
         devtools_chan: dc.map(|dc| Arc::new(Mutex::new(dc))),
         filemanager: Arc::new(Mutex::new(FileManager::new(
-            sender,
+            sender.clone(),
             pool_handle.unwrap_or_else(|| Weak::new()),
         ))),
         file_token: FileTokenCheck::NotRequired,
+        request_intercepter: Arc::new(Mutex::new(RequestIntercepter::new(sender))),
         cancellation_listener: Arc::new(Default::default()),
         timing: ServoArc::new(Mutex::new(ResourceFetchTiming::new(
             ResourceTimingType::Navigation,

components/shared/embedder/Cargo.toml

@@ -18,10 +18,14 @@ webxr = ["dep:webxr-api"]
 base = { workspace = true }
 cfg-if = { workspace = true }
 crossbeam-channel = { workspace = true }
+http = { workspace = true }
+hyper_serde = { workspace = true }
 ipc-channel = { workspace = true }
 keyboard-types = { workspace = true }
 log = { workspace = true }
 num-derive = "0.4"
+malloc_size_of = { workspace = true }
+malloc_size_of_derive = { workspace = true }
 num-traits = { workspace = true }
 serde = { workspace = true }
 servo_url = { path = "../../url" }

components/shared/embedder/lib.rs

@@ -8,9 +8,11 @@ use std::fmt::{Debug, Error, Formatter};
 
 use base::id::{PipelineId, TopLevelBrowsingContextId, WebViewId};
 use crossbeam_channel::{Receiver, Sender};
+use http::{HeaderMap, Method, StatusCode};
 use ipc_channel::ipc::IpcSender;
 use keyboard_types::KeyboardEvent;
 use log::warn;
+use malloc_size_of_derive::MallocSizeOf;
 use num_derive::FromPrimitive;
 use serde::{Deserialize, Serialize};
 use servo_url::ServoUrl;
@@ -212,6 +214,7 @@ pub enum EmbedderMsg {
     LoadStart,
     /// The load of a page has completed
     LoadComplete,
+    WebResourceRequested(WebResourceRequest, IpcSender<WebResourceResponseMsg>),
     /// A pipeline panicked. First string is the reason, second one is the backtrace.
     Panic(String, Option<String>),
     /// Open dialog to select bluetooth device.
@@ -282,6 +285,7 @@ impl Debug for EmbedderMsg {
             EmbedderMsg::SetFullscreenState(..) => write!(f, "SetFullscreenState"),
             EmbedderMsg::LoadStart => write!(f, "LoadStart"),
             EmbedderMsg::LoadComplete => write!(f, "LoadComplete"),
+            EmbedderMsg::WebResourceRequested(..) => write!(f, "WebResourceRequested"),
             EmbedderMsg::Panic(..) => write!(f, "Panic"),
             EmbedderMsg::GetSelectedBluetoothDevice(..) => write!(f, "GetSelectedBluetoothDevice"),
             EmbedderMsg::SelectFiles(..) => write!(f, "SelectFiles"),
@@ -437,3 +441,101 @@ pub struct DualRumbleEffectParams {
 pub enum GamepadHapticEffectType {
     DualRumble(DualRumbleEffectParams),
 }
+
+#[derive(Clone, Debug, Deserialize, MallocSizeOf, Serialize)]
+pub struct WebResourceRequest {
+    #[serde(
+        deserialize_with = "::hyper_serde::deserialize",
+        serialize_with = "::hyper_serde::serialize"
+    )]
+    #[ignore_malloc_size_of = "Defined in hyper"]
+    pub method: Method,
+    #[serde(
+        deserialize_with = "::hyper_serde::deserialize",
+        serialize_with = "::hyper_serde::serialize"
+    )]
+    #[ignore_malloc_size_of = "Defined in hyper"]
+    pub headers: HeaderMap,
+    pub url: ServoUrl,
+    pub is_for_main_frame: bool,
+    pub is_redirect: bool,
+}
+
+impl WebResourceRequest {
+    pub fn new(
+        method: Method,
+        headers: HeaderMap,
+        url: ServoUrl,
+        is_for_main_frame: bool,
+        is_redirect: bool,
+    ) -> Self {
+        WebResourceRequest {
+            method,
+            url,
+            headers,
+            is_for_main_frame,
+            is_redirect,
+        }
+    }
+}
+
+#[derive(Clone, Deserialize, Serialize)]
+pub enum WebResourceResponseMsg {
+    // Response of WebResourceRequest, no body included.
+    Start(WebResourceResponse),
+    // send a body chunk. It is expected Response sent before body.
+    Body(HttpBodyData),
+    // not to override the response.
+    None,
+}
+
+#[derive(Clone, Deserialize, Serialize)]
+pub enum HttpBodyData {
+    Chunk(Vec<u8>),
+    Done,
+    Cancelled,
+}
+
+#[derive(Clone, Debug, Deserialize, MallocSizeOf, Serialize)]
+pub struct WebResourceResponse {
+    pub url: ServoUrl,
+    #[serde(
+        deserialize_with = "::hyper_serde::deserialize",
+        serialize_with = "::hyper_serde::serialize"
+    )]
+    #[ignore_malloc_size_of = "Defined in hyper"]
+    pub headers: HeaderMap,
+    #[serde(
+        deserialize_with = "::hyper_serde::deserialize",
+        serialize_with = "::hyper_serde::serialize"
+    )]
+    #[ignore_malloc_size_of = "Defined in hyper"]
+    pub status_code: StatusCode,
+    pub status_message: Vec<u8>,
+}
+
+impl WebResourceResponse {
+    pub fn new(url: ServoUrl) -> WebResourceResponse {
+        WebResourceResponse {
+            url,
+            headers: HeaderMap::new(),
+            status_code: StatusCode::OK,
+            status_message: b"OK".to_vec(),
+        }
+    }
+
+    pub fn headers(mut self, headers: HeaderMap) -> WebResourceResponse {
+        self.headers = headers;
+        self
+    }
+
+    pub fn status_code(mut self, status_code: StatusCode) -> WebResourceResponse {
+        self.status_code = status_code;
+        self
+    }
+
+    pub fn status_message(mut self, status_message: Vec<u8>) -> WebResourceResponse {
+        self.status_message = status_message;
+        self
+    }
+}

ports/servoshell/desktop/tracing.rs

@@ -154,6 +154,7 @@ mod from_servo {
                 Self::WebViewClosed(..) => target!("WebViewClosed"),
                 Self::WebViewFocused(..) => target!("WebViewFocused"),
                 Self::WebViewBlurred => target!("WebViewBlurred"),
+                Self::WebResourceRequested(..) => target!("WebResourceRequested"),
                 Self::AllowUnload(..) => target!("AllowUnload"),
                 Self::Keyboard(..) => target!("Keyboard"),
                 Self::ClearClipboardContents => target!("ClearClipboardContents"),

ports/servoshell/desktop/webview.rs

@@ -936,6 +936,7 @@ where
                         }
                     }
                 },
+                EmbedderMsg::WebResourceRequested(_web_resource_request, _response_sender) => {},
                 EmbedderMsg::Shutdown => {
                     self.shutdown_requested = true;
                 },

ports/servoshell/egl/servo_glue.rs

@@ -645,7 +645,8 @@ impl ServoGlue {
                 EmbedderMsg::EventDelivered(..) |
                 EmbedderMsg::PlayGamepadHapticEffect(..) |
                 EmbedderMsg::StopGamepadHapticEffect(..) |
-                EmbedderMsg::ClearClipboardContents => {},
+                EmbedderMsg::ClearClipboardContents |
+                EmbedderMsg::WebResourceRequested(..) => {},
             }
         }