TextEditor: Tweak the refactoroverlay painting for HighDPI

The lightbulb was slightly scaled up on HighDPI.

Change-Id: Iea00532ebbf93ce185651ec01364efdbd924a067
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/texteditor/refactoroverlay.cpp

@@ -81,9 +81,10 @@ void RefactorOverlay::paintMarker(const RefactorMarker& marker, QPainter *painte
     if (icon.isNull())
         icon = m_icon;
 
+    const qreal devicePixelRatio = painter->device()->devicePixelRatio();
     const QSize proposedIconSize = QSize(m_editor->fontMetrics().width(QLatin1Char(' ')) + 3,
-                                         cursorRect.height());
-    const QSize actualIconSize = icon.actualSize(proposedIconSize);
+                                         cursorRect.height()) * devicePixelRatio;
+    const QSize actualIconSize = icon.actualSize(proposedIconSize) / devicePixelRatio;
 
     const int y = cursorRect.top() + ((cursorRect.height() - actualIconSize.height()) / 2);
     const int x = cursorRect.right();