It started out as busywork, but it does many separate things. If I could
start over, I'd take them apart into multiple commits:
1. Remove G_ENABLE_DEBUG around GDK_DEBUG_*() calls
This is not needed at all, the calls themselves take care of it.
2. Remove G_ENABLE_DEBUG around profiling code
This now enables profiling support in release builds.
3. Stop poking _gdk_debug_flags and use GDK_DEBUG_CHECK()
This was old code that was never updated.
4. Make !G_ENABLE_DEBUG turn off GDK_DEBUG_CHECK()
The code used to
#define GDK_DEBUG_CHECK(...) false
#define GDK_DEBUG(...)
which would compile away all the code inside those macros. This
means a lot of variable definitions and debug utility functions
would suddenly no longer be used and cause compiler errors.
Add a new debug flag for dmabuf-related information,
and use it in gdkdmabuftexture.c.
This will let us separate out dmabuf debug spew from
opengl debug spew.
Fractional scaling with the GL renderer is
experimental for now, so we disable it unless
GDK_DEBUG=gl-fractional is set.
This will give us time to work out the kinks.
