Fixes a segfault, where a wl_buffer was destroyed while in use. Also it
allows us to replace the custom caching mechanism and instead find
existing buffers by their destroy listener.
SurfaceViewWidget is now always a child of a GtkGraphicsOffload and
handles the GdkTexture on its own. This way the extra GtkPicture is no
longer needed and also the frame_callback of the Wayland server can be
implemented.
they can still be put on the filesystem and will be read from there
preferentially, though overriding assets in this way can confuse
some creatively written apps and cause them to crash.
Now that we have a reasonably well working SurfaceView implementation,
it is actually cleaner to just implement GLSurfaceView the way AOSP
does. In fact, their code doesn't have any weird dependencies, and
can mostly be used as-is.
The AOSP code is pure Java, which means we had to implement some
EGL wrappers.
This change fixes issues with Wayland (it only ever worked because
the pbuffers were allocated using an XWayland EGLDisplay), and
with resizing (which we simply didn't support), all while getting
rid of quite some (arguably not very readable) LoC.
