[iOS] Ensure that GraphicsServices is initialized before calling GSFontPurgeFontCache().
https://bugs.webkit.org/show_bug.cgi?id=173616
<rdar://problem/
30780050>
Reviewed by Chris Dumez.
Source/WebCore:
Fix for crash in GSFontPurgeFontCache() seen in apps embedding WebKit.
Ensure GSFontInitialize() has been called first, since the former depends on state
set up by this function.
* page/cocoa/MemoryReleaseCocoa.mm:
(WebCore::platformReleaseMemory):
* platform/spi/ios/GraphicsServicesSPI.h:
WebKitLibraries:
* WebKitPrivateFrameworkStubs/iOS/10/GraphicsServices.framework/GraphicsServices.tbd:
git-svn-id: https://svn.webkit.org/repository/webkit/trunk@218643
268f45cc-cd09-0410-ab3c-
d52691b4dbfc