Change PaintLayer::m_layoutObject to a reference.

third_party/WebKit/Source/core/paint/FramePainter.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/paint/FramePainter.h"
 
 #include "core/editing/markers/DocumentMarkerController.h"
 #include "core/frame/FrameView.h"
 #include "core/inspector/InspectorInstrumentation.h"
 #include "core/inspector/InspectorTraceEvents.h"
@@ skipping 146 matching lines @@
   GlobalPaintFlags localPaintFlags = globalPaintFlags;
   if (document->printing())
     localPaintFlags |=
         GlobalPaintFlattenCompositingLayers | GlobalPaintPrinting;
 
   PaintLayer* rootLayer = layoutView->layer();
 
 #if DCHECK_IS_ON()
   layoutView->assertSubtreeIsLaidOut();
   LayoutObject::SetLayoutNeededForbiddenScope forbidSetNeedsLayout(
-      *rootLayer->layoutObject());
+      rootLayer->layoutObject());
 #endif
 
   PaintLayerPainter layerPainter(*rootLayer);
 
   float deviceScaleFactor =
-      blink::deviceScaleFactor(rootLayer->layoutObject()->frame());
+      blink::deviceScaleFactor(rootLayer->layoutObject().frame());
   context.setDeviceScaleFactor(deviceScaleFactor);
 
   layerPainter.paint(context, LayoutRect(rect), localPaintFlags);
 
   if (rootLayer->containsDirtyOverlayScrollbars())
     layerPainter.paintOverlayScrollbars(context, LayoutRect(rect),
                                         localPaintFlags);
 
   // Regions may have changed as a result of the visibility/z-index of element
   // changing.
@@ skipping 62 matching lines @@
 
   bar.paint(context, CullRect(rect));
 }
 
 const FrameView& FramePainter::frameView() {
   DCHECK(m_frameView);
   return *m_frameView;
 }
 
 }  // namespace blink