+2016-03-30 Simon Fraser <simon.fraser@apple.com>
+
+ [iOS WK2] Avoid creating tiles that are too large for rendering
+ https://bugs.webkit.org/show_bug.cgi?id=156050
+ rdar://problem/25424541
+
+ Reviewed by Darin Adler.
+
+ In the case of a WKWebView which is sized large enough to show an entire document
+ (for example, when enclosed inside a UIScrollView), we would create tiles that were
+ larger than CoreAnimation was willing to deal with.
+
+ * platform/graphics/ca/TileController.cpp:
+ (WebCore::TileController::tileSize): Take the device scale, and the max IOSurface size
+ into account when computing the max tile size.
+ * platform/graphics/cocoa/IOSurface.mm:
+ (IOSurface::maximumSize): CoreAnimation imposes limits in addition to the size reported
+ by IOSurfaceGetPropertyMaximum(), namely an 8k cap, so mimic that here.
+ (IOSurface::ensurePlatformContext): Typo.
+