Now that we only have one compositor, there's no reason to access the
compositor functions through a vtable. Remove the MetaCompositor virtualization
and make the clutter code implement the meta_compositor_* functions
directly.
Move the checks for the compositor being NULL from the vtable wrappers
to the calling code (most of them were already there, so just a few
needed to be added)
Note: the compositor is actually hard-coded on at the moment and the plan
is to remove the non-composited code entirely, so the checks are
added only to keep things neat: they have no practical effect.
http://bugzilla.gnome.org/show_bug.cgi?id=581813
In order to properly track the stacking order for override-redirect
windows, move meta_compositor_sync_stack() call into MetaStackTracker.
In the new location, we sync the stack as a before-redraw idle function,
rather then using the freeze-thaw facilities of MetaStack. This is
simpler, and also properly compresses multiple stack changes on
notifications received from the X server.
http://bugzilla.gnome.org/show_bug.cgi?id=585984
Wedging override-redirect windows into the constraint code in stack.c
results in Mutter getting confused about the stacking order of
these windows with respect to other windows, and may also in some
cases cause Mutter to restack override-redirect windows.
core/stack-tracker.c core/stack-tracker.h: MetaStackTracker - combine
events received from the X server with local changes we have made
to come up with the best possible idea of what the stacking order
is at any one point in time.
core/screen.c core/screen-private.h: Create a MetaStackTracker for
the screen.
core/display.c: Feed relevant events to MetaStackTracker
core/frame.c core/screen.c core/stack.c: When we make changes to the
stacking order or add windows, record those changes immediatley
in MetaStackTracker so we have the information without waiting
for a round-trip.
include/ui.h ui/ui.c: meta_ui_create_frame_window add a return value
for the X request serial used to create the window.
http://bugzilla.gnome.org/show_bug.cgi?id=585984
