[wpe-webkit] WPE WebKit on libhybris drivers

[Alfred Neumayer]

Hello,

I am working on integrating WPE WebKit as a new browser for Ubuntu
Touch, the smart phone OS (which isn't dead but maintained by
community members) using libhybris drivers.

In a nutshell libhybris wraps GLESv2 and EGL for Android into glibc
libraries + some Wayland listeners for passing those buffers between a
client and a server. Right now this allows for working WPE WebKit with
the WPEQtView (since UT uses QML for UI mostly) but at the cost of
performance.

Something causes the frame completion handler in the WPEQtViewBackend
to get called at roughly 30fps, which isn't ideal and I have ruled
out:

- OpenGL ES not getting used
- Buffer passing between the UIProcess and the WebProcess not working
- DisplayVBlank timer stalling redraws

to be the causes, so I am wondering how to approach the debugging of
this issue further.

What I have noticed is that opening webkit://gpu allows smooth
scrolling until the first few frames have finished drawing, so roughly
the first half of a second is considerably fluid.

I really would like to reach the fluidity of recent WebKitGTK. :)

Thank you.