Use refs for non-null GraphicsContext, Scrollbar, etc. in scrollbar related code

third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp

 /*
  * Copyright (C) 2009, 2010, 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 2230 matching lines @@
 
 static void paintScrollbar(const Scrollbar* scrollbar, GraphicsContext& context, const IntRect& clip)
 {
     if (!scrollbar)
         return;
 
     const IntRect& scrollbarRect = scrollbar->frameRect();
     TransformRecorder transformRecorder(context, *scrollbar, AffineTransform::translation(-scrollbarRect.x(), -scrollbarRect.y()));
     IntRect transformedClip = clip;
     transformedClip.moveBy(scrollbarRect.location());
-    scrollbar->paint(&context, CullRect(transformedClip));
+    scrollbar->paint(context, CullRect(transformedClip));
 }
 
 // The following should be kept in sync with the code computing potential_new_recorded_viewport in
 // cc::DisplayListRecordingSource::UpdateAndExpandInvalidation() before we keep only one copy of the algorithm.
 static const int kPixelDistanceToRecord = 4000;
 
 IntRect CompositedLayerMapping::recomputeInterestRect(const GraphicsLayer* graphicsLayer) const
 {
     FloatRect graphicsLayerBounds(FloatPoint(), graphicsLayer->size());
 
@@ skipping 144 matching lines @@
     } else if (graphicsLayer == m_squashingLayer.get()) {
         for (size_t i = 0; i < m_squashedLayers.size(); ++i)
             doPaintTask(m_squashedLayers[i], *graphicsLayer, paintLayerFlags, &context, interestRect);
     } else if (graphicsLayer == layerForHorizontalScrollbar()) {
         paintScrollbar(m_owningLayer.scrollableArea()->horizontalScrollbar(), context, interestRect);
     } else if (graphicsLayer == layerForVerticalScrollbar()) {
         paintScrollbar(m_owningLayer.scrollableArea()->verticalScrollbar(), context, interestRect);
     } else if (graphicsLayer == layerForScrollCorner()) {
         IntPoint scrollCornerAndResizerLocation = m_owningLayer.scrollableArea()->scrollCornerAndResizerRect().location();
         CullRect cullRect(enclosingIntRect(interestRect));
-        ScrollableAreaPainter(*m_owningLayer.scrollableArea()).paintScrollCorner(&context, -scrollCornerAndResizerLocation, cullRect);
-        ScrollableAreaPainter(*m_owningLayer.scrollableArea()).paintResizer(&context, -scrollCornerAndResizerLocation, cullRect);
+        ScrollableAreaPainter(*m_owningLayer.scrollableArea()).paintScrollCorner(context, -scrollCornerAndResizerLocation, cullRect);
+        ScrollableAreaPainter(*m_owningLayer.scrollableArea()).paintResizer(context, -scrollCornerAndResizerLocation, cullRect);
     }
     InspectorInstrumentation::didPaint(m_owningLayer.layoutObject(), graphicsLayer, &context, LayoutRect(interestRect));
 #if ENABLE(ASSERT)
     if (Page* page = layoutObject()->frame()->page())
         page->setIsPainting(false);
 #endif
 }
 
 bool CompositedLayerMapping::isTrackingPaintInvalidations() const
 {
@@ skipping 173 matching lines @@
     } else if (graphicsLayer == m_scrollingBlockSelectionLayer.get()) {
         name = "Scrolling Block Selection Layer";
     } else {
         ASSERT_NOT_REACHED();
     }
 
     return name;
 }
 
 } // namespace blink