Transforms are flattened in snapshots of on-screen WKWebViews

-[WKWebView _snapshotRect:intoImageOfWidth:completionHandler:] gives a software rendering of the view, which flattens transforms, even when the view is on-screen and the render server can capture the unflattened layers.

<rdar://problem/20282863>

Created attachment 249358 [details]
Have the render server capture a layer tree snapshot if the view is on-screen

[Tim Horton]

Comment on attachment 249358 [details]
Have the render server capture a layer tree snapshot if the view is on-screen

(Anders had some comments on IRC).

[Anders Carlsson]

Comment on attachment 249358 [details]
Have the render server capture a layer tree snapshot if the view is on-screen

View in context: https://bugs.webkit.org/attachment.cgi?id=249358&action=review

> Source/WebKit2/UIProcess/API/Cocoa/WKWebView.mm:2518
> +        std::unique_ptr<WebCore::IOSurface> surface = WebCore::IOSurface::create(WebCore::expandedIntSize(WebCore::FloatSize(imageSize)), WebCore::ColorSpaceDeviceRGB);

Please use auto here.

> Source/WebKit2/UIProcess/API/Cocoa/WKWebView.mm:2521
> +        completionHandler(surface->createImage().autorelease());

Please don't autorelease the image.

Fixed in <http://trac.webkit.org/r181910>.

[Alexey Proskuryakov]

iOS EWS is still broken: https://webkit-queues.appspot.com/results/5624952967397376

In file included from /Volumes/Data/EWS/WebKit/Source/WebCore/platform/ios/LegacyTileCache.mm:38:
/Volumes/Data/EWS/WebKit/Source/WebCore/platform/spi/cocoa/QuartzCoreSPI.h:121:118: error: unknown type name 'IOSurfaceRef'
EXTERN_C void CARenderServerRenderLayerWithTransform(mach_port_t server_port, uint32_t client_id, uint64_t layer_id, IOSurfaceRef iosurface, int32_t ox, int32_t oy, const CATransform3D *matrix);

(In reply to comment #6)
> iOS EWS is still broken:
> https://webkit-queues.appspot.com/results/5624952967397376
> 
> In file included from
> /Volumes/Data/EWS/WebKit/Source/WebCore/platform/ios/LegacyTileCache.mm:38:
> /Volumes/Data/EWS/WebKit/Source/WebCore/platform/spi/cocoa/QuartzCoreSPI.h:
> 121:118: error: unknown type name 'IOSurfaceRef'
> EXTERN_C void CARenderServerRenderLayerWithTransform(mach_port_t
> server_port, uint32_t client_id, uint64_t layer_id, IOSurfaceRef iosurface,
> int32_t ox, int32_t oy, const CATransform3D *matrix);

Tried to fix that in <http://trac.webkit.org/r181931>.

[Alexey Proskuryakov]

That broke the Mac build (all open source ones at least).

And again in <http://trac.webkit.org/r181933>.