* platform/graphics/Gradient.h: Forward-declare CGContextRef.
This might even make it possible to remove the include of
<CoreGraphics/CoreGraphics.h> for PLATFORM(WIN), but I did not
do that at this time because I don't want to break the Windows
build when fixing the Chromium build.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@75145 268f45cc-cd09-0410-ab3c-d52691b4dbfc