Mark the cursor as rendered after performing compositing

If a cursor animation is driven purely by frame callbacks and kwin
uses hardware cursors, the cpu usage may spike to 100%.

This change addresses that issue by sending frame callbacks after a
compositing cycle has been performed.

composite.cpp

@@ -705,6 +705,9 @@ void Compositor::performCompositing()
                 surface->frameRendered(currentTime);
             }
         }
+        if (!kwinApp()->platform()->isCursorHidden()) {
+            Cursors::self()->currentCursor()->markAsRendered();
+        }
     }
 
     // Stop here to ensure *we* cause the next repaint schedule - not some effect

plugins/platforms/drm/drm_backend.cpp

@@ -544,8 +544,6 @@ void DrmBackend::setCursor()
             }
         }
     }
-
-    Cursors::self()->currentCursor()->markAsRendered();
 }
 
 void DrmBackend::updateCursor()

plugins/platforms/x11/windowed/x11windowed_backend.cpp

@@ -481,7 +481,6 @@ void X11WindowedBackend::createCursor(const QImage &srcImage, const QPoint &hots
     }
     m_cursor = cid;
     xcb_flush(m_connection);
-    Cursors::self()->currentCursor()->markAsRendered();
 }
 
 xcb_window_t X11WindowedBackend::rootWindow() const

plugins/scenes/opengl/scene_opengl.cpp

@@ -601,9 +601,6 @@ void SceneOpenGL2::paintCursor()
     binder.shader()->setUniform(GLShader::ModelViewProjectionMatrix, mvp);
     m_cursorTexture->render(QRegion(cursorRect), cursorRect);
     m_cursorTexture->unbind();
-
-    cursor->markAsRendered();
-
     glDisable(GL_BLEND);
 }
 

plugins/scenes/qpainter/scene_qpainter.cpp

@@ -163,7 +163,6 @@ void SceneQPainter::paintCursor()
     const QPoint cursorPos = cursor->pos();
     const QPoint hotspot = cursor->hotspot();
     m_painter->drawImage(cursorPos - hotspot, img);
-    cursor->markAsRendered();
 }
 
 void SceneQPainter::paintEffectQuickView(EffectQuickView *w)