Support <link rel=dns-prefetch> on iOS and remove privacy-invasive DNS prefetching features

[annevk]

634cc1e

Support <link rel=dns-prefetch> on iOS and remove privacy-invasive DNS prefetching features
https://bugs.webkit.org/show_bug.cgi?id=285744
rdar://144699889

Reviewed by Alex Christensen.

This was initially landed as 288915@main and backed out in 288920@main
because it was not understood all functionality was enabled for macOS.

This commit wants to reland 288915@main as-is, but now with the
understanding that this removes privacy-invasive and proprietary DNS
prefetching features from macOS, while continuing to support the
standardized <link rel=dns-prefetch> and extending that support to iOS
and other WebKit ports.

* LayoutTests/http/tests/misc/dns-prefetch-control-expected.txt:
* LayoutTests/http/tests/misc/dns-prefetch-control.html:
* LayoutTests/http/tests/misc/resources/dns-prefetch-control.py: Removed.
* Source/WTF/Scripts/Preferences/UnifiedWebPreferences.yaml:
* Source/WebCore/DerivedSources-output.xcfilelist:
* Source/WebCore/DerivedSources.make:
* Source/WebCore/dom/Document.cpp:
(WebCore::Document::processMetaHttpEquiv):
(WebCore::Document::initDNSPrefetch): Deleted.
(WebCore::Document::isDNSPrefetchEnabled const): Deleted.
(WebCore::Document::parseDNSPrefetchControlHeader): Deleted.
* Source/WebCore/dom/Document.h:
* Source/WebCore/html/HTMLAnchorElement.cpp:
(WebCore::HTMLAnchorElement::attributeChanged):
* Source/WebCore/html/LinkRelAttribute.cpp:
* Source/WebCore/loader/FrameLoader.cpp:
(WebCore::FrameLoader::didBeginDocument):
* Source/WebCore/loader/LinkLoader.cpp:
(WebCore::LinkLoader::loadLink):
* Source/WebCore/page/Chrome.cpp:
(WebCore::Chrome::mouseDidMoveOverElement):
* Source/WebCore/page/Page.cpp:
(WebCore::Page::dnsPrefetchingStateChanged): Deleted.
* Source/WebCore/page/Page.h:
* Source/WebCore/page/SettingsBase.cpp:
(WebCore::SettingsBase::dnsPrefetchingEnabledChanged): Deleted.
* Source/WebCore/page/SettingsBase.h:
* Source/WebCore/platform/network/HTTPHeaderNames.in:
* Source/WebCore/platform/network/ResourceResponseBase.cpp:
(WebCore::isSafeCrossOriginResponseHeader):
* Source/WebKit/UIProcess/API/C/WKPreferences.cpp:
(WKPreferencesSetDNSPrefetchingEnabled):
(WKPreferencesGetDNSPrefetchingEnabled):
(WKPreferencesSetRestrictedHTTPResponseAccess):
* Source/WebKit/UIProcess/API/C/WKPreferencesRef.h:
* Source/WebKit/UIProcess/API/Cocoa/WKPreferences.mm:
(-[WKPreferences _setDNSPrefetchingEnabled:]):
(-[WKPreferences _dnsPrefetchingEnabled]):
* Source/WebKit/UIProcess/API/Cocoa/WKPreferencesPrivate.h:
* Source/WebKit/UIProcess/API/glib/WebKitSettings.cpp:
(webkit_settings_class_init):
(webkit_settings_get_enable_dns_prefetching):
(webkit_settings_set_enable_dns_prefetching):
* Source/WebKit/UIProcess/API/glib/WebKitSettings.h.in:
* Source/WebKit/UIProcess/Extensions/Cocoa/_WKWebExtensionDeclarativeNetRequestRule.mm:
(isHeaderNameValid):
* Source/WebKit/WebProcess/WebPage/ios/WebPageIOS.mm:
(WebKit::WebPage::sendTapHighlightForNodeIfNecessary):
* Source/WebKitLegacy/mac/WebView/WebPreferenceKeysPrivate.h:
* Source/WebKitLegacy/mac/WebView/WebPreferences.mm:
(-[WebPreferences isDNSPrefetchingEnabled]):
(-[WebPreferences setDNSPrefetchingEnabled:]):
* Source/WebKitLegacy/mac/WebView/WebPreferencesPrivate.h:
* Tools/TestWebKitAPI/Tests/WebKitGLib/TestWebKitSettings.cpp:
(testWebKitSettings):

Canonical link: https://commits.webkit.org/290327@main

417f925

Misc	iOS, visionOS, tvOS & watchOS	macOS	Linux	Windows
❌ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 win
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2	✅ 🧪 win-tests
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 api-wpe
	✅ 🧪 ios-wk2-wpt	✅ 🧪 mac-wk1	✅ 🛠 wpe-cairo
✅ 🛠 🧪 jsc	✅ 🧪 api-ios	✅ 🧪 mac-wk2	✅ 🛠 gtk
✅ 🛠 🧪 jsc-arm64	✅ 🛠 vision	✅ 🧪 mac-AS-debug-wk2	✅ 🧪 gtk-wk2
	✅ 🛠 vision-sim	✅ 🧪 mac-wk2-stress	✅ 🧪 api-gtk
	✅ 🧪 vision-wk2	✅ 🧪 mac-intel-wk2	✅ 🛠 playstation
✅ 🛠 🧪 unsafe-merge	✅ 🛠 tv	✅ 🛠 mac-safer-cpp	✅ 🛠 jsc-armv7
	✅ 🛠 tv-sim		❌ 🧪 jsc-armv7-tests
	✅ 🛠 watch
	✅ 🛠 watch-sim

[webkit-early-warning-system]

EWS run on current version of this PR (hash 417f925)

Details

Misc	iOS, visionOS, tvOS & watchOS	macOS	Linux	Windows
❌ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 win
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2	✅ 🧪 win-tests
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 api-wpe
	✅ 🧪 ios-wk2-wpt	✅ 🧪 mac-wk1	✅ 🛠 wpe-cairo
✅ 🛠 🧪 jsc	✅ 🧪 api-ios	✅ 🧪 mac-wk2	✅ 🛠 gtk
✅ 🛠 🧪 jsc-arm64	✅ 🛠 vision	✅ 🧪 mac-AS-debug-wk2	✅ 🧪 gtk-wk2
	✅ 🛠 vision-sim	✅ 🧪 mac-wk2-stress	✅ 🧪 api-gtk
	✅ 🧪 vision-wk2	✅ 🧪 mac-intel-wk2	✅ 🛠 playstation
✅ 🛠 🧪 unsafe-merge	✅ 🛠 tv	✅ 🛠 mac-safer-cpp	✅ 🛠 jsc-armv7
	✅ 🛠 tv-sim		❌ 🧪 jsc-armv7-tests
	✅ 🛠 watch
	✅ 🛠 watch-sim

[webkit-commit-queue]

Committed 290327@main (634cc1e): https://commits.webkit.org/290327@main

Reviewed commits have been landed. Closing PR #40488 and removing active labels.