Implement quota limitation for keepalive Fetch requests

Implement quota limitation for keepalive Fetch requests
https://bugs.webkit.org/show_bug.cgi?id=175482

Reviewed by Sam Weinig and Youenn Fablet.

LayoutTests/imported/w3c:

* web-platform-tests/fetch/api/basic/scheme-about.any-expected.txt:
* web-platform-tests/fetch/api/basic/scheme-about.any.worker-expected.txt:
* web-platform-tests/fetch/api/cors/cors-multiple-origins-expected.txt:
* web-platform-tests/fetch/api/cors/cors-multiple-origins-worker-expected.txt:
* web-platform-tests/fetch/api/cors/cors-preflight-star.any-expected.txt:
* web-platform-tests/fetch/api/cors/cors-preflight-star.any.worker-expected.txt:
* web-platform-tests/fetch/http-cache/cc-request-expected.txt:
Rebaseline tests now that we provide a more helpful error message when rejecting
the fetch() promise.

* web-platform-tests/fetch/api/request/request-keepalive-quota-expected.txt:
Rebaseline test for keepalive Fetch requests quota which is now passing.

Source/WebCore:

Implement quota limitation for keepalive Fetch requests as per:
- https://fetch.spec.whatwg.org/#http-network-or-cache-fetch (Step 9)

This partly works for Beacon as well, meaning that no Beacon with a body
over 64Kb can be sent. However, we don't keep track about wether or not
beacon loads are inflight or not.

Also update CachedResourceLoader::requestResource() so that the caller
can get a ResourceError when it returns null. This is useful for both
Fetch and Beacon to return better error messages.

Test: http/wpt/beacon/beacon-quota.html

* CMakeLists.txt:
* Modules/beacon/NavigatorBeacon.cpp:
(WebCore::NavigatorBeacon::sendBeacon):
* Modules/fetch/FetchBodyOwner.cpp:
(WebCore::FetchBodyOwner::BlobLoader::didReceiveResponse):
(WebCore::FetchBodyOwner::BlobLoader::didFail):
* Modules/fetch/FetchBodyOwner.h:
* Modules/fetch/FetchLoader.cpp:
(WebCore::FetchLoader::start):
(WebCore::FetchLoader::didFail):
* Modules/fetch/FetchLoaderClient.h:
* Modules/fetch/FetchResponse.cpp:
(WebCore::FetchResponse::BodyLoader::didFail):
* Modules/fetch/FetchResponse.h:
* WebCore.xcodeproj/project.pbxproj:
* loader/DocumentThreadableLoader.cpp:
(WebCore::DocumentThreadableLoader::loadRequest):
* loader/cache/CachedResource.cpp:
(WebCore::CachedResource::load):
* loader/cache/CachedResource.h:
(WebCore::CachedResource::isMainOrMediaOrIconOrRawResource const):
* loader/cache/CachedResourceLoader.cpp:
(WebCore::createResource):
(WebCore::CachedResourceLoader::requestImage):
(WebCore::CachedResourceLoader::requestFont):
(WebCore::CachedResourceLoader::requestTextTrack):
(WebCore::CachedResourceLoader::requestCSSStyleSheet):
(WebCore::CachedResourceLoader::requestUserCSSStyleSheet):
(WebCore::CachedResourceLoader::requestScript):
(WebCore::CachedResourceLoader::requestXSLStyleSheet):
(WebCore::CachedResourceLoader::requestSVGDocument):
(WebCore::CachedResourceLoader::requestLinkResource):
(WebCore::CachedResourceLoader::requestMedia):
(WebCore::CachedResourceLoader::requestIcon):
(WebCore::CachedResourceLoader::requestRawResource):
(WebCore::CachedResourceLoader::requestBeaconResource):
(WebCore::CachedResourceLoader::requestMainResource):
(WebCore::CachedResourceLoader::requestResource):
(WebCore::CachedResourceLoader::preload):
* loader/cache/CachedResourceLoader.h:
* loader/cache/KeepaliveRequestTracker.cpp: Added.
(WebCore::KeepaliveRequestTracker::~KeepaliveRequestTracker):
(WebCore::KeepaliveRequestTracker::canLoadRequest):
(WebCore::KeepaliveRequestTracker::registerRequest):
(WebCore::KeepaliveRequestTracker::responseReceived):
(WebCore::KeepaliveRequestTracker::notifyFinished):
(WebCore::KeepaliveRequestTracker::unregisterRequest):
* loader/cache/KeepaliveRequestTracker.h: Added.
* platform/network/FormData.cpp:
(WebCore::FormDataElement::lengthInBytes const):
(WebCore::FormData::lengthInBytes const):
* platform/network/FormData.h:

LayoutTests:

* fast/xmlhttprequest/xmlhttprequest-nonexistent-file-expected.txt:
* http/tests/contentextensions/async-xhr-onerror-expected.txt:
* http/tests/security/contentSecurityPolicy/block-all-mixed-content/insecure-xhr-asynchronous-in-iframe-expected.txt:
* http/tests/security/contentSecurityPolicy/block-all-mixed-content/insecure-xhr-asynchronous-in-main-frame-expected.txt:
* http/tests/security/mixedContent/insecure-xhr-in-main-frame-expected.txt:
Rebaseline a few tests now that we provide a more helpful error message when an XHR is failing synchronously.

* http/wpt/beacon/beacon-quota-expected.txt: Added.
* http/wpt/beacon/beacon-quota.html: Added.
Add layout test coverage for keepalive Fetch requests quota in the context of sendBeacon().
The second part of the test is still failing because WebCore does not currently know when
ping loads (e.g. beacon loads) complete. This will be addressed via Bug 175443.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@220751 268f45cc-cd09-0410-ab3c-d52691b4dbfc