Rename Item::scheduleRepaint()

One can think that Item::scheduleRepaint() will trigger repaint of the
whole item, but it actually only schedules the next frame. If nothing
has changed on the screen, no real painting will be done unless maybe if
the rendering backend needs to repair the back buffer.

src/item.cpp

@@ -364,7 +364,7 @@ void Item::scheduleRepaint(const QRegion &region)
     }
 }
 
-void Item::scheduleRepaint()
+void Item::scheduleFrame()
 {
     if (kwinApp()->platform()->isPerScreenRenderingEnabled()) {
         const QRect geometry = mapToGlobal(rect());

src/item.h

@@ -92,7 +92,7 @@ public:
     void stackChildren(const QList<Item *> &children);
 
     void scheduleRepaint(const QRegion &region);
-    void scheduleRepaint();
+    void scheduleFrame();
     QRegion repaints(int screen) const;
     void resetRepaints(int screen);
 

src/surfaceitem_wayland.cpp

@@ -90,7 +90,7 @@ void SurfaceItemWayland::handleSurfaceSizeChanged()
 void SurfaceItemWayland::handleSurfaceCommitted()
 {
     if (m_surface->hasFrameCallbacks()) {
-        scheduleRepaint();
+        scheduleFrame();
     }
 }
 

src/surfaceitem_x11.cpp

@@ -37,7 +37,7 @@ SurfaceItemX11::~SurfaceItemX11()
 void SurfaceItemX11::processDamage()
 {
     m_isDamaged = true;
-    scheduleRepaint();
+    scheduleFrame();
 }
 
 bool SurfaceItemX11::fetchDamage()