Bug 112150

Created attachment 192732 [details] WIP patch This is my first attempt to enable texture mapper backing store tiles rendering directly into GL textures using cairo gl. The idea is to use cairo gl backend to render graphics layers into GPU memory skipping rendering in software memory. In force composting mode it would allow to render whole page in GPU memory. In theory it should improve performance of page rendering and help the integration of cairo gl with WebKit GTK. This is work in progress patch and I want to use it as a starting point for the discussion to find the best approach possible. In order to try the patch you should enable force compositing and webgl in Source/WebKit2/Shared/WebPreferencesStore.h. Also you should apply Alex's 2D canvas patch first as I reuse some bits of it for this patch.