A service worker task should be done when its NetworkResourceLoader is don - #77267

…ence its loader

rdar://188341702
https://bugs.webkit.org/show_bug.cgi?id=327816

Reviewed by NOBODY (OOPS!).

NetworkResourceLoader can race the service worker fetch with the network.
In case of redirection for a navigation load, we might receive the network redirection before the service worker answer.
In that case, NetworkResourceLoader would set its service worker task to null and would either create a new one directly or would restart the load.
That makes the NetworkResourceLoader forgetting about the service worker task.
If NetworkResourceLoader dies, the service worker fetch task might start when its context connection is created and would crash.

To prevent this, we make sure to cancel the service worker fetch task when NetworkResourceLoader is no longer interested in it.
We do this in NetworkResourceLoader::continueWillSendRequest and for good measure, we also do this in NetworkResourceLoader::~NetworkResourceLoader.

While writing the test, we hit an issue with an ASSERT in SWServerWorker::setWorkerScripts.
This happens as the test is trying to create several fetch events on the same service worker that is not yet running.
We would then load scripts for every of these fetch events, which is unnecessary.

To prevent this, we introduce a HashMap of the workers whose scripts are being loaded.
We store the callbacks to call when the scripts are loaded.
If a worker is already in this HashMap, it means that scripts are being loaded and we do not need to request the store to load them again.

Test: http/wpt/service-workers/service-worker-fetch-task-cancel-on-redirect.https.html

* LayoutTests/http/wpt/service-workers/resources/redirect.py: Added.
* LayoutTests/http/wpt/service-workers/service-worker-fetch-task-cancel-on-redirect.https-expected.txt: Added.
* LayoutTests/http/wpt/service-workers/service-worker-fetch-task-cancel-on-redirect.https.html: Added.
* Source/WebCore/workers/service/server/SWServer.cpp:
(WebCore::SWServer::close):
(WebCore::SWServer::loadWorkerScripts):
* Source/WebCore/workers/service/server/SWServer.h:
* Source/WebKit/NetworkProcess/NetworkResourceLoader.cpp:
(WebKit::NetworkResourceLoader::continueWillSendRequest):
* Source/WebKit/NetworkProcess/ServiceWorker/ServiceWorkerFetchTask.cpp:
(WebKit::ServiceWorkerFetchTask::start):
(WebKit::ServiceWorkerFetchTask::startFetch):