devtools: Use request destination as cause_type in NetworkEventActor (#38162)

The cause_type in NetworkEventActor was derived from a hard-coded
pattern match on the request URL file extension.

This patch replaces the hard-coded pattern matching with the Destination
field of Request, to provide a better alignment with the Fetch
specification.

Testing: Updated unit tests.
Fixes: #38151

---------

Signed-off-by: Kingsley Yung <kingsley@kkoyung.dev>

components/net/http_loader.rs

@@ -397,6 +397,7 @@ fn prepare_devtools_request(
     pipeline_id: PipelineId,
     connect_time: Duration,
     send_time: Duration,
+    destination: Destination,
     is_xhr: bool,
     browsing_context_id: BrowsingContextId,
 ) -> ChromeToDevtoolsControlMsg {
@@ -414,6 +415,7 @@ fn prepare_devtools_request(
             .as_secs() as i64,
         connect_time,
         send_time,
+        destination,
         is_xhr,
         browsing_context_id,
     };
@@ -488,6 +490,7 @@ pub fn send_early_httprequest_to_devtools(request: &mut Request, context: &Fetch
             time_stamp: 0,
             connect_time: Duration::from_millis(0),
             send_time: Duration::from_millis(0),
+            destination: request.destination,
             is_xhr: false,
             browsing_context_id,
         };
@@ -586,6 +589,7 @@ async fn obtain_response(
     source_is_null: bool,
     pipeline_id: &Option<PipelineId>,
     request_id: Option<&str>,
+    destination: Destination,
     is_xhr: bool,
     context: &FetchContext,
     fetch_terminated: UnboundedSender<bool>,
@@ -780,6 +784,7 @@ async fn obtain_response(
                                 pipeline_id,
                                 (connect_end - connect_start).unsigned_abs(),
                                 (send_end - send_start).unsigned_abs(),
+                                destination,
                                 is_xhr,
                                 browsing_context_id,
                             ))
@@ -1959,6 +1964,7 @@ async fn http_network_fetch(
             .unwrap_or(false),
         &request.pipeline_id,
         Some(&request_id),
+        request.destination,
         is_xhr,
         context,
         fetch_terminated_sender,

components/net/tests/fetch.rs

@@ -1339,6 +1339,7 @@ fn test_fetch_with_devtools() {
         time_stamp: devhttprequests.1.time_stamp,
         connect_time: devhttprequests.1.connect_time,
         send_time: devhttprequests.1.send_time,
+        destination: Destination::None,
         is_xhr: true,
         browsing_context_id: TEST_WEBVIEW_ID.0,
     };

components/net/tests/http_loader.rs

@@ -333,6 +333,7 @@ fn test_request_and_response_data_with_network_messages() {
         time_stamp: devhttprequests.1.time_stamp,
         connect_time: devhttprequests.1.connect_time,
         send_time: devhttprequests.1.send_time,
+        destination: Destination::Document,
         is_xhr: false,
         browsing_context_id: TEST_WEBVIEW_ID.0,
     };