Don't call FontCache invalidation callbacks when clearing FontCaches in response to memory pressure

[heycam]

639f82d

Don't call FontCache invalidation callbacks when clearing FontCaches in response to memory pressure
https://bugs.webkit.org/show_bug.cgi?id=251560
<rdar://problem/105197603>

Reviewed by NOBODY (OOPS!).

As of https://bugs.webkit.org/show_bug.cgi?id=249561, we call
FontCache::invalidate in response to memory pressure, in order to clear
some cache data. But we can end up calling FontCache invalidation
callbacks and FontSelector invalidation callbacks, both of which cause a
full style rebuild. This is not necessary when the FontCache is being
invalidated due to memory pressure.

We thread through the ShouldRunInvalidationCallbacks value through to
individual FontCache::invalidate calls so that we can skip informing the
FontSelectors about the invalidation.

The ShouldRunInvalidationCallbacks argument is made non-default, to
avoid future misuse.

* Source/WebCore/platform/ThreadGlobalData.cpp:
(WebCore::ThreadGlobalData::destroy):
* Source/WebCore/platform/graphics/FontCache.cpp:
(WebCore::FontCache::invalidate):
(WebCore::FontCache::invalidateAllFontCaches):
* Source/WebCore/platform/graphics/FontCache.h:
* Source/WebCore/platform/graphics/cocoa/FontCacheCoreText.cpp:
(WebCore::fontCacheRegisteredFontsChangedNotificationCallback):
(WebCore::FontCache::platformReleaseNoncriticalMemory):
* Source/WebCore/testing/InternalSettings.cpp:
(WebCore::InternalSettings::setShouldMockBoldSystemFontForAccessibility):
* Source/WebCore/testing/Internals.cpp:
(WebCore::Internals::invalidateFontCache):
* Source/WebKit/WebProcess/WebPage/ios/WebPageIOS.mm:
(WebKit::WebPage::contentSizeCategoryDidChange):
* Source/WebKit/WebProcess/WebProcess.cpp:
(WebKit::WebProcess::terminate):
* Source/WebKit/WebProcess/cocoa/WebProcessCocoa.mm:
(WebKit::WebProcess::accessibilityPreferencesDidChange):

639f82d

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 wincairo
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🛠 gtk
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 gtk-wk2
	✅ 🧪 api-ios	✅ 🧪 mac-wk1	✅ 🧪 api-gtk
	✅ 🛠 tv	✅ 🧪 mac-wk2
	✅ 🛠 tv-sim	✅ 🧪 mac-AS-debug-wk2
	✅ 🛠 watch	✅ 🧪 mac-wk2-stress
	✅ 🛠 watch-sim

[webkit-early-warning-system]

EWS run on previous version of this PR (hash 1b29d3a)

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	⏳ 🛠 wincairo
✅ 🧪 bindings	✅ 🛠 ios-sim	❌ 🛠 mac-AS-debug	✅ 🛠 gtk
✅ 🧪 webkitperl	🧪 ios-wk2	✅ 🧪 api-mac	🧪 gtk-wk2
	🧪 api-ios	🧪 mac-wk1	🧪 api-gtk
	⏳ 🛠 tv	✅ 🧪 mac-wk2	⏳ 🛠 jsc-armv7
	✅ 🛠 tv-sim	❌ 🧪 mac-AS-debug-wk2	⏳ 🧪 jsc-armv7-tests
	⏳ 🛠 watch	✅ 🧪 mac-wk2-stress
	✅ 🛠 watch-sim

[webkit-early-warning-system]

EWS run on current version of this PR (hash 639f82d)

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 wincairo
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🛠 gtk
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 gtk-wk2
	✅ 🧪 api-ios	✅ 🧪 mac-wk1	✅ 🧪 api-gtk
	✅ 🛠 tv	✅ 🧪 mac-wk2
	✅ 🛠 tv-sim	✅ 🧪 mac-AS-debug-wk2
	✅ 🛠 watch	✅ 🧪 mac-wk2-stress
	✅ 🛠 watch-sim

[heycam]

This is not having the memory impact I'd expect. Back to draft.