Widgets: remove some unused includes

Remove some unused includes in source files.

Change-Id: I5c43fd10fa1a179664ad8cbf4988f9bdb96d8af8
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>
(cherry picked from commit 69053eea3fa858e7885dbac5e5d0bcd6ed618174)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

src/widgets/kernel/qlayout.cpp

@@ -3,20 +3,10 @@
 
 #include "qlayout.h"
 
-#include "qapplication.h"
 #include "qlayoutengine_p.h"
-#if QT_CONFIG(menubar)
-#include "qmenubar.h"
-#endif
-#if QT_CONFIG(toolbar)
-#include "qtoolbar.h"
-#endif
-#if QT_CONFIG(sizegrip)
-#include "qsizegrip.h"
-#endif
+#include "qguiapplication.h"
 #include "qevent.h"
 #include "qstyle.h"
-#include "qvariant.h"
 #include "qwidget_p.h"
 #include "qlayout_p.h"
 

src/widgets/kernel/qlayoutitem.cpp

@@ -5,12 +5,6 @@
 
 #include "qapplication.h"
 #include "qlayoutengine_p.h"
-#if QT_CONFIG(menubar)
-#include "qmenubar.h"
-#endif
-#if QT_CONFIG(toolbar)
-#include "qtoolbar.h"
-#endif
 #include "qevent.h"
 #include "qstyle.h"
 #include "qvariant.h"

src/widgets/widgets/qmenu.cpp

@@ -30,9 +30,6 @@
 #include "qmenubar_p.h"
 #endif
 #include "qwidgetaction.h"
-#if QT_CONFIG(toolbutton)
-#include "qtoolbutton.h"
-#endif
 #include "qpushbutton.h"
 #if QT_CONFIG(tooltip)
 #include "qtooltip.h"

src/widgets/widgets/qmenubar.cpp

@@ -15,9 +15,6 @@
 #if QT_CONFIG(mainwindow)
 #include <qmainwindow.h>
 #endif
-#if QT_CONFIG(toolbar)
-#include <qtoolbar.h>
-#endif
 #if QT_CONFIG(toolbutton)
 #include <qtoolbutton.h>
 #endif

src/widgets/widgets/qtoolbar.cpp

@@ -4,9 +4,6 @@
 #include "qtoolbar.h"
 
 #include <qapplication.h>
-#if QT_CONFIG(combobox)
-#include <qcombobox.h>
-#endif
 #if QT_CONFIG(draganddrop)
 #include <qdrag.h>
 #endif
@@ -14,13 +11,7 @@
 #include <qlayout.h>
 #include <qmainwindow.h>
 #include <qmenu.h>
-#if QT_CONFIG(menubar)
-#include <qmenubar.h>
-#endif
 #include <qmimedata.h>
-#if QT_CONFIG(rubberband)
-#include <qrubberband.h>
-#endif
 #include <qstylepainter.h>
 #include <qstyleoption.h>
 #include <qtoolbutton.h>