Use WindowAttributes and WindowGeometry everywhere where the xcb commands
had already been used.
Introduces another wrapper for overlay window and a subclass for query
tree which also wrapps the children command.
The extension handling is removed from kwinglobals and moved into the
xcbutils in KWin core in namespace KWin::Xcb. The motivation for this
change is that the Extensions are only used in KWin core and are marked
as internal. So there is no need to have them in the library.
What remains in Extensions are the non-native pixmaps. This will be
removed once we are on Qt 5 as QPixmap can no longer reference an XPixmap.
The remaining code in kwinglobals also still initialize the XLib versions
of extensions emitting events. It seems like there are no XEvents emitted
if not done so even if the extension is correctly initialized with xcb.
This needs to be removed once the event handling is ported over to xcb.
REVIEW: 107832
The HAVE_XCOMPOSITE_OVERLAY define had not been moved to the new
overlaywindow.cpp file causing the OverlayWindow to not be created
at all. In fact after moving the define to the new file the code
did not even compile as that code parts still used m_overlayWindow
instead of m_window.
The regression would have been easy to spot when testing with all
backends as the GLES/EGL backend still requires the overlay window.
CCMAIL: a.arlt@stud.uni-heidelberg.de
All the functionality of Overlay Window is moved to its own class
OverlayWindow. It is created and owned by class Scene, since almost
all function calls are called from this class.
REVIEW: 101866
