Remove unused method QKeyMapper::clearMappings()

The plumbing from QKeyMapper to the platform specific key mappers
via QPA was never done, so this method is unused. The code path
in QKeyMapper that would trigger it would be changeKeyboard(),
but that's already handled in QCocoaKeyMapper, and wouldn't be
initiated from the cross platform code in any case.

Change-Id: Ibc0c419627fc0430d028945038c1f2fbafe42d4b
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>

src/gui/kernel/qkeymapper.cpp

@@ -89,8 +89,6 @@ QList<int> QKeyMapper::possibleKeys(QKeyEvent *e)
 extern bool qt_sendSpontaneousEvent(QObject *receiver, QEvent *event); // in qapplication_*.cpp
 void QKeyMapper::changeKeyboard()
 {
-    instance()->d_func()->clearMappings();
-
     // ## TODO: Support KeyboardLayoutChange on QPA
 #if 0
     // inform all toplevel widgets of the change
@@ -125,11 +123,6 @@ QKeyMapperPrivate::QKeyMapperPrivate()
 }
 
 QKeyMapperPrivate::~QKeyMapperPrivate()
-{
-    // clearMappings();
-}
-
-void QKeyMapperPrivate::clearMappings()
 {
 }
 

src/gui/kernel/qkeymapper_p.h

@@ -88,7 +88,6 @@ public:
     QKeyMapperPrivate();
     ~QKeyMapperPrivate();
 
-    void clearMappings();
     QList<int> possibleKeys(QKeyEvent *e);
 
     QLocale keyboardInputLocale;

src/plugins/platforms/cocoa/qcocoakeymapper.h

@@ -92,7 +92,6 @@ private:
     bool updateKeyboard();
     void deleteLayouts();
     KeyboardLayoutItem *keyMapForKey(unsigned short macVirtualKey, QChar unicodeKey) const;
-    void clearMappings();
 
     QCFType<TISInputSourceRef> m_currentInputSource = nullptr;
 

src/plugins/platforms/cocoa/qcocoakeymapper.mm

@@ -440,12 +440,6 @@ void QCocoaKeyMapper::deleteLayouts()
     }
 }
 
-void QCocoaKeyMapper::clearMappings()
-{
-    deleteLayouts();
-    updateKeyboard();
-}
-
 static constexpr Qt::KeyboardModifiers modifierCombinations[] = {
     Qt::NoModifier,                                             // 0
     Qt::ShiftModifier,                                          // 1