Use a boolean hasCompositedLayerMapping() accessor instead of the pointer

Source/core/rendering/CompositedLayerMapping.cpp

Index: Source/core/rendering/CompositedLayerMapping.cpp
diff --git a/Source/core/rendering/CompositedLayerMapping.cpp b/Source/core/rendering/CompositedLayerMapping.cpp
index 8a061b5a8dcc0642bbc6967acc61b5ae58051c86..228a13f0c85c162cd9adea8d8d0813493f62eeaa 100644
--- a/Source/core/rendering/CompositedLayerMapping.cpp
+++ b/Source/core/rendering/CompositedLayerMapping.cpp
@@ -469,7 +469,7 @@ bool CompositedLayerMapping::updateGraphicsLayerConfiguration()
         m_graphicsLayer->setContentsClippingMaskLayer(m_childClippingMaskLayer.get());
 
     if (m_owningLayer->reflectionInfo()) {
-        if (m_owningLayer->reflectionInfo()->reflectionLayer()->compositedLayerMapping()) {
+        if (m_owningLayer->reflectionInfo()->reflectionLayer()->hasCompositedLayerMapping()) {
             GraphicsLayer* reflectionLayer = m_owningLayer->reflectionInfo()->reflectionLayer()->compositedLayerMapping()->mainGraphicsLayer();
             m_graphicsLayer->setReplicatedByLayer(reflectionLayer);
         }
@@ -556,7 +556,7 @@ void CompositedLayerMapping::updateGraphicsLayerGeometry()
     // We compute everything relative to the enclosing compositing layer.
     IntRect ancestorCompositingBounds;
     if (compAncestor) {
-        ASSERT(compAncestor->compositedLayerMapping());
+        ASSERT(compAncestor->hasCompositedLayerMapping());
         ancestorCompositingBounds = pixelSnappedIntRect(compAncestor->compositedLayerMapping()->compositedBounds());
     }
 
@@ -705,7 +705,7 @@ void CompositedLayerMapping::updateGraphicsLayerGeometry()
         m_backgroundLayer->setOffsetFromRenderer(m_graphicsLayer->offsetFromRenderer());
     }
 
-    if (m_owningLayer->reflectionInfo() && m_owningLayer->reflectionInfo()->reflectionLayer()->compositedLayerMapping()) {
+    if (m_owningLayer->reflectionInfo() && m_owningLayer->reflectionInfo()->reflectionLayer()->hasCompositedLayerMapping()) {
         CompositedLayerMapping* reflectionCompositedLayerMapping = m_owningLayer->reflectionInfo()->reflectionLayer()->compositedLayerMapping();
         reflectionCompositedLayerMapping->updateGraphicsLayerGeometry();
 
@@ -1357,7 +1357,7 @@ static bool hasVisibleNonCompositingDescendant(RenderLayer* parent)
         size_t listSize = normalFlowList->size();
         for (size_t i = 0; i < listSize; ++i) {
             RenderLayer* curLayer = normalFlowList->at(i)->layer();
-            if (!curLayer->compositedLayerMapping()
+            if (!curLayer->hasCompositedLayerMapping()
                 && (curLayer->hasVisibleContent() || hasVisibleNonCompositingDescendant(curLayer)))
                 return true;
         }
@@ -1372,7 +1372,7 @@ static bool hasVisibleNonCompositingDescendant(RenderLayer* parent)
             size_t listSize = negZOrderList->size();
             for (size_t i = 0; i < listSize; ++i) {
                 RenderLayer* curLayer = negZOrderList->at(i)->layer();
-                if (!curLayer->compositedLayerMapping()
+                if (!curLayer->hasCompositedLayerMapping()
                     && (curLayer->hasVisibleContent() || hasVisibleNonCompositingDescendant(curLayer)))
                     return true;
             }
@@ -1382,7 +1382,7 @@ static bool hasVisibleNonCompositingDescendant(RenderLayer* parent)
             size_t listSize = posZOrderList->size();
             for (size_t i = 0; i < listSize; ++i) {
                 RenderLayer* curLayer = posZOrderList->at(i)->layer();
-                if (!curLayer->compositedLayerMapping()
+                if (!curLayer->hasCompositedLayerMapping()
                     && (curLayer->hasVisibleContent() || hasVisibleNonCompositingDescendant(curLayer)))
                     return true;
             }