[Background Fetch] Throw DOMException for responseReady on abort.

According to the spec, responseReady in BackgroundFetchRecord should
throw an AbortError DOMException if the fetch was abandoned.

https://wicg.github.io/background-fetch/#create-record-objects (2.4.3)

Change-Id: Ieadf278acd061e05b8822014d0934f050fcac702
Reviewed-on: https://chromium-review.googlesource.com/c/1283692
Commit-Queue: Rayan Kanso <rayankans@chromium.org>
Reviewed-by: Peter Beverloo <peter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#600769}

third_party/WebKit/LayoutTests/external/wpt/background-fetch/abort.https.window.js

@@ -59,4 +59,16 @@ backgroundFetchTest(async (test, backgroundFetch) => {
     };
   });
 
-}, 'Calling BackgroundFetchRegistration.abort sets the correct fields and responses are still available');
+}, 'Calling BackgroundFetchRegistration.abort sets the correct fields and responses are still available');
\ No newline at end of file
+
+backgroundFetchTest(async (test, backgroundFetch) => {
+  const registration = await backgroundFetch.fetch(
+      uniqueId(), '/serviceworker/resources/slow-response.php');
+  assert_true(await registration.abort());
+
+  const {results} = await getMessageFromServiceWorker();
+  assert_equals(results.length, 1);
+  assert_false(results[0].response);
+  assert_equals(results[0].name, 'AbortError');
+
+}, 'An aborted fetch throws a DOM exception when accessing an incomplete record', 'sw-abort.js');
\ No newline at end of file

third_party/WebKit/LayoutTests/external/wpt/background-fetch/service_workers/sw-abort.js

+importScripts('sw-helpers.js');
+
+async function getFetchResult(record) {
+  try {
+    await record.responseReady;
+  } catch (e) {
+    return {
+      response: false,
+      name: e.name,
+    };
+  }
+
+  return {
+    response: true,
+  };
+}
+self.addEventListener('backgroundfetchabort', event => {
+  event.waitUntil(
+    event.registration.matchAll()
+      .then(records =>
+            Promise.all(records.map(record => getFetchResult(record))))
+      .then(results => sendMessageToDocument({results})));
+});

third_party/blink/renderer/modules/background_fetch/background_fetch_record.cc

@@ -10,8 +10,9 @@
 namespace blink {
 
 BackgroundFetchRecord::BackgroundFetchRecord(Request* request,
-                                             Response* response)
-    : request_(request), response_(response) {
+                                             Response* response,
+                                             bool aborted)
+    : request_(request), response_(response), aborted_(aborted) {
   DCHECK(request_);
 }
 
@@ -23,15 +24,25 @@ ScriptPromise BackgroundFetchRecord::responseReady(ScriptState* script_state) {
         new ResponseReadyProperty(ExecutionContext::From(script_state), this,
                                   ResponseReadyProperty::kResponseReady);
   }
-  if (!response_) {
-    return ScriptPromise::Reject(
+
+  if (response_) {
+    DCHECK(response_);
+    response_ready_property_->Resolve(response_);
+    return response_ready_property_->Promise(script_state->World());
+  }
+
+  if (aborted_) {
+    return ScriptPromise::RejectWithDOMException(
         script_state,
-        V8ThrowException::CreateTypeError(script_state->GetIsolate(),
-                                          "The response is not available."));
+        DOMException::Create(
+            DOMExceptionCode::kAbortError,
+            "The fetch was aborted before the record was processed."));
   }
-  DCHECK(response_);
-  response_ready_property_->Resolve(response_);
-  return response_ready_property_->Promise(script_state->World());
+
+  return ScriptPromise::Reject(
+      script_state,
+      V8ThrowException::CreateTypeError(script_state->GetIsolate(),
+                                        "The response is not available."));
 }
 
 Request* BackgroundFetchRecord::request() const {

third_party/blink/renderer/modules/background_fetch/background_fetch_record.h

@@ -21,8 +21,7 @@ class MODULES_EXPORT BackgroundFetchRecord final : public ScriptWrappable {
   DEFINE_WRAPPERTYPEINFO();
 
  public:
-  explicit BackgroundFetchRecord(Request* request,
-                                 Response* response = nullptr);
+  BackgroundFetchRecord(Request* request, Response* response, bool aborted);
   ~BackgroundFetchRecord() override;
 
   Request* request() const;
@@ -38,6 +37,9 @@ class MODULES_EXPORT BackgroundFetchRecord final : public ScriptWrappable {
   Member<Request> request_;
   Member<Response> response_;
   Member<ResponseReadyProperty> response_ready_property_;
+
+  // Whether this record belongs to a fetch that was aborted.
+  bool aborted_;
 };
 
 }  // namespace blink

third_party/blink/renderer/modules/background_fetch/background_fetch_registration.cc

@@ -238,11 +238,19 @@ void BackgroundFetchRegistration::DidGetMatchingRequests(
   HeapVector<Member<BackgroundFetchRecord>> to_return;
   to_return.ReserveInitialCapacity(settled_fetches.size());
   for (const auto& fetch : settled_fetches) {
-    BackgroundFetchRecord* record = new BackgroundFetchRecord(
-        Request::Create(script_state, fetch->request),
-        fetch->response ? Response::Create(script_state, *fetch->response)
-                        : nullptr);
-    to_return.push_back(record);
+    Request* request = Request::Create(script_state, fetch->request);
+
+    Response* response = fetch->response
+                             ? Response::Create(script_state, *fetch->response)
+                             : nullptr;
+
+    bool aborted =
+        failure_reason_ ==
+            mojom::BackgroundFetchFailureReason::CANCELLED_FROM_UI ||
+        failure_reason_ ==
+            mojom::BackgroundFetchFailureReason::CANCELLED_BY_DEVELOPER;
+
+    to_return.push_back(new BackgroundFetchRecord(request, response, aborted));
   }
 
   if (!return_all) {