(WIP) Paint property hierarchy approach 1 of 2

third_party/WebKit/Source/platform/graphics/GraphicsLayer.cpp

Index: third_party/WebKit/Source/platform/graphics/GraphicsLayer.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/GraphicsLayer.cpp b/third_party/WebKit/Source/platform/graphics/GraphicsLayer.cpp
index 21f225a6b10ccf0622d76da6c59e1f248f62dedd..dbbf81d4d35f277186534aa4dceba0c31c7c47e1 100644
--- a/third_party/WebKit/Source/platform/graphics/GraphicsLayer.cpp
+++ b/third_party/WebKit/Source/platform/graphics/GraphicsLayer.cpp
@@ -299,7 +299,7 @@ void GraphicsLayer::paintGraphicsLayerContents(GraphicsContext& context, const I
         m_debugInfo.clearAnnotatedInvalidateRects();
     incrementPaintCount();
 #ifndef NDEBUG
-    if (m_displayItemList && contentsOpaque() && s_drawDebugRedFill) {
+    if (m_paintArtifact && contentsOpaque() && s_drawDebugRedFill) {
         FloatRect rect(FloatPoint(), size());
         if (!DrawingRecorder::useCachedDrawingIfPossible(context, *this, DisplayItem::DebugRedFill)) {
             DrawingRecorder recorder(context, *this, DisplayItem::DebugRedFill, rect);
@@ -797,8 +797,8 @@ void GraphicsLayer::setSize(const FloatSize& size)
 
 #ifndef NDEBUG
     // The red debug fill needs to be invalidated if the layer resizes.
-    if (m_displayItemList)
-        m_displayItemList->invalidateUntracked(displayItemClient());
+    if (m_paintArtifact)
+        m_paintArtifact->displayItemList().invalidateUntracked(displayItemClient());
 #endif
 }
 
@@ -1189,11 +1189,11 @@ void GraphicsLayer::didScroll()
     }
 }
 
-DisplayItemList* GraphicsLayer::displayItemList()
+PaintArtifact* GraphicsLayer::paintArtifact()
 {
-    if (!m_displayItemList)
-        m_displayItemList = DisplayItemList::create();
-    return m_displayItemList.get();
+    if (!m_paintArtifact)
+        m_paintArtifact = PaintArtifact::create();
+    return m_paintArtifact.get();
 }
 
 } // namespace blink