Added minimal class docs for QWindow to make it visible.

Change-Id: Ibed2279ba5454547fb4060005e805a11221b3732
Reviewed-by: Samuel Rødal <samuel.rodal@nokia.com>

src/gui/kernel/qwindow.cpp

@@ -56,6 +56,20 @@
 
 QT_BEGIN_NAMESPACE
 
+/*!
+    \class QWindow
+    \brief The QWindow class encapsulates an independent windw in a Windowing System.
+
+    A window that is supplied a parent become a native child window of
+    their parent window.
+
+    Windows can potentially use a lot of memory. A usual measurement is
+    width * height * depth. A window might also include multiple buffers
+    to support double and triple buffering. To release a windows memory
+    resources, the destroy() function.
+
+ */
+
 QWindow::QWindow(QScreen *targetScreen)
     : QObject(*new QWindowPrivate(), 0)
     , QSurface(QSurface::Window)
@@ -624,6 +638,12 @@ void QWindow::setWindowIcon(const QImage &icon) const
     qDebug() << "unimplemented:" << __FILE__ << __LINE__;
 }
 
+
+
+/*!
+    Releases the native platform resources associated with this window.
+ */
+
 void QWindow::destroy()
 {
     Q_D(QWindow);