Use a boolean hasCompositedLayerMapping() accessor instead of the pointer

Source/core/rendering/RenderLayerCompositor.cpp

Index: Source/core/rendering/RenderLayerCompositor.cpp
diff --git a/Source/core/rendering/RenderLayerCompositor.cpp b/Source/core/rendering/RenderLayerCompositor.cpp
index 508131b24e551951947d7c3f9d0c3242e07e1e8c..7499793f48486b14921767b34a0c920b7c54519d 100644
--- a/Source/core/rendering/RenderLayerCompositor.cpp
+++ b/Source/core/rendering/RenderLayerCompositor.cpp
@@ -302,7 +302,7 @@ void RenderLayerCompositor::didChangeVisibleRect()
 
 bool RenderLayerCompositor::hasAnyAdditionalCompositedLayers(const RenderLayer* rootLayer) const
 {
-    return m_compositedLayerCount > (rootLayer->compositedLayerMapping() ? 1 : 0);
+    return m_compositedLayerCount > (rootLayer->hasCompositedLayerMapping() ? 1 : 0);
 }
 
 void RenderLayerCompositor::updateCompositingRequirementsState()
@@ -453,12 +453,11 @@ void RenderLayerCompositor::updateCompositingLayers(CompositingUpdateType update
         // Host the document layer in the RenderView's root layer.
         if (RuntimeEnabledFeatures::overlayFullscreenVideoEnabled() && isMainFrame()) {
             RenderVideo* video = findFullscreenVideoRenderer(&m_renderView->document());
-            if (video) {
+            if (video && video->hasCompositedLayerMapping()) {
                 CompositedLayerMapping* compositedLayerMapping = video->compositedLayerMapping();
-                if (compositedLayerMapping) {
-                    childList.clear();
-                    childList.append(compositedLayerMapping->mainGraphicsLayer());
-                }
+                ASSERT(compositedLayerMapping);

[hartmanng, 2013/11/04 22:56:09]

Personally, I'd just take this out - seems inconsistent to ASSERT this here, but
everywhere else just checking hasCompositedLayerMapping() is enough.

+                childList.clear();
+                childList.append(compositedLayerMapping->mainGraphicsLayer());
             }
         }
         // Even when childList is empty, don't drop out of compositing mode if there are
@@ -521,7 +520,7 @@ bool RenderLayerCompositor::allocateOrClearCompositedLayerMapping(RenderLayer* l
     if (needsToBeComposited(layer)) {
         enableCompositingMode();
 
-        if (!layer->compositedLayerMapping()) {
+        if (!layer->hasCompositedLayerMapping()) {
             // If we need to repaint, do so before allocating the compositedLayerMapping
             if (shouldRepaint == CompositingChangeRepaintNow)
                 repaintOnCompositingChange(layer);
@@ -544,13 +543,14 @@ bool RenderLayerCompositor::allocateOrClearCompositedLayerMapping(RenderLayer* l
         if (layer->compositedLayerMapping()->updateRequiresOwnBackingStoreForIntrinsicReasons())
             compositedLayerMappingChanged = true;
     } else {
-        if (layer->compositedLayerMapping()) {
+        if (layer->hasCompositedLayerMapping()) {
             // If we're removing the compositedLayerMapping from a reflection, clear the source GraphicsLayer's pointer to
             // its replica GraphicsLayer. In practice this should never happen because reflectee and reflection
             // are both either composited, or not composited.
             if (layer->isReflection()) {
                 RenderLayer* sourceLayer = toRenderLayerModelObject(layer->renderer()->parent())->layer();
-                if (CompositedLayerMapping* compositedLayerMapping = sourceLayer->compositedLayerMapping()) {
+                if (sourceLayer->hasCompositedLayerMapping()) {
+                    CompositedLayerMapping* compositedLayerMapping = sourceLayer->compositedLayerMapping();
                     ASSERT(compositedLayerMapping->mainGraphicsLayer()->replicaLayer() == layer->compositedLayerMapping()->mainGraphicsLayer());
                     compositedLayerMapping->mainGraphicsLayer()->setReplicatedByLayer(0);
                 }
@@ -604,7 +604,7 @@ bool RenderLayerCompositor::updateLayerCompositingState(RenderLayer* layer, Comp
 
     // See if we need content or clipping layers. Methods called here should assume
     // that the compositing state of descendant layers has not been updated yet.
-    if (layer->compositedLayerMapping() && layer->compositedLayerMapping()->updateGraphicsLayerConfiguration())
+    if (layer->hasCompositedLayerMapping() && layer->compositedLayerMapping()->updateGraphicsLayerConfiguration())
         layerChanged = true;
 
     return layerChanged;
@@ -663,7 +663,7 @@ void RenderLayerCompositor::layerWasAdded(RenderLayer* /*parent*/, RenderLayer*
 
 void RenderLayerCompositor::layerWillBeRemoved(RenderLayer* parent, RenderLayer* child)
 {
-    if (!child->compositedLayerMapping() || parent->renderer()->documentBeingDestroyed())
+    if (!child->hasCompositedLayerMapping() || parent->renderer()->documentBeingDestroyed())
         return;
 
     removeViewportConstrainedLayer(child);
@@ -980,12 +980,12 @@ void RenderLayerCompositor::computeCompositingRequirements(RenderLayer* ancestor
 void RenderLayerCompositor::setCompositingParent(RenderLayer* childLayer, RenderLayer* parentLayer)
 {
     ASSERT(!parentLayer || childLayer->ancestorCompositingLayer() == parentLayer);
-    ASSERT(childLayer->compositedLayerMapping());
+    ASSERT(childLayer->hasCompositedLayerMapping());
 
     // It's possible to be called with a parent that isn't yet composited when we're doing
     // partial updates as required by painting or hit testing. Just bail in that case;
     // we'll do a full layer update soon.
-    if (!parentLayer || !parentLayer->compositedLayerMapping())
+    if (!parentLayer || !parentLayer->hasCompositedLayerMapping())
         return;
 
     if (parentLayer) {
@@ -1000,7 +1000,7 @@ void RenderLayerCompositor::setCompositingParent(RenderLayer* childLayer, Render
 
 void RenderLayerCompositor::removeCompositedChildren(RenderLayer* layer)
 {
-    ASSERT(layer->compositedLayerMapping());
+    ASSERT(layer->hasCompositedLayerMapping());
 
     GraphicsLayer* hostingLayer = layer->compositedLayerMapping()->parentForSublayers();
     hostingLayer->removeAllChildren();
@@ -1032,15 +1032,15 @@ void RenderLayerCompositor::rebuildCompositingLayerTree(RenderLayer* layer, Vect
         pixelsAddedByPromotingAllTransitions = 0.0;
     }
 
-    CompositedLayerMapping* currentCompositedLayerMapping = layer->compositedLayerMapping();
-    if (currentCompositedLayerMapping) {
+    if (layer->hasCompositedLayerMapping()) {
+        CompositedLayerMapping* currentCompositedLayerMapping = layer->compositedLayerMapping();
         // The compositing state of all our children has been updated already, so now
         // we can compute and cache the composited bounds for this layer.
         currentCompositedLayerMapping->updateCompositedBounds();
 
         if (layer->reflectionInfo()) {
             RenderLayer* reflectionLayer = layer->reflectionInfo()->reflectionLayer();
-            if (reflectionLayer->compositedLayerMapping())
+            if (reflectionLayer->hasCompositedLayerMapping())
                 reflectionLayer->compositedLayerMapping()->updateCompositedBounds();
         }
 
@@ -1064,7 +1064,7 @@ void RenderLayerCompositor::rebuildCompositingLayerTree(RenderLayer* layer, Vect
     // If this layer has a compositedLayerMapping, then that is where we place subsequent children GraphicsLayers.
     // Otherwise children continue to append to the child list of the enclosing layer.
     Vector<GraphicsLayer*> layerChildren;
-    Vector<GraphicsLayer*>& childList = currentCompositedLayerMapping ? layerChildren : childLayersOfEnclosingLayer;
+    Vector<GraphicsLayer*>& childList = layer->hasCompositedLayerMapping() ? layerChildren : childLayersOfEnclosingLayer;
 
 #if !ASSERT_DISABLED
     LayerListMutationDetector mutationChecker(layer->stackingNode());
@@ -1076,15 +1076,16 @@ void RenderLayerCompositor::rebuildCompositingLayerTree(RenderLayer* layer, Vect
             rebuildCompositingLayerTree(curNode->layer(), childList, depth + 1);
 
         // If a negative z-order child is compositing, we get a foreground layer which needs to get parented.
-        if (currentCompositedLayerMapping && currentCompositedLayerMapping->foregroundLayer())
-            childList.append(currentCompositedLayerMapping->foregroundLayer());
+        if (layer->hasCompositedLayerMapping() && layer->compositedLayerMapping()->foregroundLayer())
+            childList.append(layer->compositedLayerMapping()->foregroundLayer());
     }
 
     RenderLayerStackingNodeIterator iterator(*layer->stackingNode(), NormalFlowChildren | PositiveZOrderChildren);
     while (RenderLayerStackingNode* curNode = iterator.next())
         rebuildCompositingLayerTree(curNode->layer(), childList, depth + 1);
 
-    if (currentCompositedLayerMapping) {
+    if (layer->hasCompositedLayerMapping()) {
+        CompositedLayerMapping* currentCompositedLayerMapping = layer->compositedLayerMapping();
         bool parented = false;
         if (layer->renderer()->isRenderPart())
             parented = parentFrameContentLayers(toRenderPart(layer->renderer()));
@@ -1267,7 +1268,7 @@ bool RenderLayerCompositor::parentFrameContentLayers(RenderPart* renderer)
         return false;
 
     RenderLayer* layer = renderer->layer();
-    if (!layer->compositedLayerMapping())
+    if (!layer->hasCompositedLayerMapping())
         return false;
 
     CompositedLayerMapping* compositedLayerMapping = layer->compositedLayerMapping();
@@ -1283,14 +1284,15 @@ bool RenderLayerCompositor::parentFrameContentLayers(RenderPart* renderer)
 // This just updates layer geometry without changing the hierarchy.
 void RenderLayerCompositor::updateLayerTreeGeometry(RenderLayer* layer)
 {
-    if (CompositedLayerMapping* compositedLayerMapping = layer->compositedLayerMapping()) {
+    if (layer->hasCompositedLayerMapping()) {
+        CompositedLayerMapping* compositedLayerMapping = layer->compositedLayerMapping();
         // The compositing state of all our children has been updated already, so now
         // we can compute and cache the composited bounds for this layer.
         compositedLayerMapping->updateCompositedBounds();
 
         if (layer->reflectionInfo()) {
             RenderLayer* reflectionLayer = layer->reflectionInfo()->reflectionLayer();
-            if (reflectionLayer->compositedLayerMapping())
+            if (reflectionLayer->hasCompositedLayerMapping())
                 reflectionLayer->compositedLayerMapping()->updateCompositedBounds();
         }
 
@@ -1313,20 +1315,19 @@ void RenderLayerCompositor::updateLayerTreeGeometry(RenderLayer* layer)
 // Recurs down the RenderLayer tree until its finds the compositing descendants of compositingAncestor and updates their geometry.
 void RenderLayerCompositor::updateCompositingDescendantGeometry(RenderLayerStackingNode* compositingAncestor, RenderLayer* layer, bool compositedChildrenOnly)
 {
-    if (layer->stackingNode() != compositingAncestor) {
-        if (CompositedLayerMapping* compositedLayerMapping = layer->compositedLayerMapping()) {
-            compositedLayerMapping->updateCompositedBounds();
-
-            if (layer->reflectionInfo()) {
-                RenderLayer* reflectionLayer = layer->reflectionInfo()->reflectionLayer();
-                if (reflectionLayer->compositedLayerMapping())
-                    reflectionLayer->compositedLayerMapping()->updateCompositedBounds();
-            }
+    if (layer->stackingNode() != compositingAncestor && layer->hasCompositedLayerMapping()) {
+        CompositedLayerMapping* compositedLayerMapping = layer->compositedLayerMapping();
+        compositedLayerMapping->updateCompositedBounds();
 
-            compositedLayerMapping->updateGraphicsLayerGeometry();
-            if (compositedChildrenOnly)
-                return;
+        if (layer->reflectionInfo()) {
+            RenderLayer* reflectionLayer = layer->reflectionInfo()->reflectionLayer();
+            if (reflectionLayer->hasCompositedLayerMapping())
+                reflectionLayer->compositedLayerMapping()->updateCompositedBounds();
         }
+
+        compositedLayerMapping->updateGraphicsLayerGeometry();
+        if (compositedChildrenOnly)
+            return;
     }
 
     if (layer->reflectionInfo())
@@ -1420,7 +1421,7 @@ void RenderLayerCompositor::clearMappingForRenderLayerIncludingDescendants(Rende
     if (!layer)
         return;
 
-    if (layer->compositedLayerMapping()) {
+    if (layer->hasCompositedLayerMapping()) {
         removeViewportConstrainedLayer(layer);
         layer->clearCompositedLayerMapping();
     }
@@ -1532,7 +1533,7 @@ CompositingReasons RenderLayerCompositor::directReasonsForCompositing(const Rend
 // but a sibling in the z-order hierarchy.
 bool RenderLayerCompositor::clippedByAncestor(const RenderLayer* layer) const
 {
-    if (!layer->compositedLayerMapping() || !layer->parent())
+    if (!layer->hasCompositedLayerMapping() || !layer->parent())
         return false;
 
     const RenderLayer* compositingAncestor = layer->ancestorCompositingLayer();
@@ -1637,7 +1638,7 @@ bool RenderLayerCompositor::requiresCompositingForPlugin(RenderObject* renderer)
     RenderWidget* pluginRenderer = toRenderWidget(renderer);
     // If we can't reliably know the size of the plugin yet, don't change compositing state.
     if (pluginRenderer->needsLayout())
-        return pluginRenderer->hasLayer() && pluginRenderer->layer()->compositedLayerMapping();
+        return pluginRenderer->hasLayer() && pluginRenderer->layer()->hasCompositedLayerMapping();
 
     // Don't go into compositing mode if height or width are zero, or size is 1x1.
     IntRect contentBox = pixelSnappedIntRect(pluginRenderer->contentBoxRect());
@@ -1663,7 +1664,7 @@ bool RenderLayerCompositor::requiresCompositingForFrame(RenderObject* renderer)
 
     // If we can't reliably know the size of the iframe yet, don't change compositing state.
     if (renderer->needsLayout())
-        return frameRenderer->hasLayer() && frameRenderer->layer()->compositedLayerMapping();
+        return frameRenderer->hasLayer() && frameRenderer->layer()->hasCompositedLayerMapping();
 
     // Don't go into compositing mode if height or width are zero.
     IntRect contentBox = pixelSnappedIntRect(frameRenderer->contentBoxRect());
@@ -1833,7 +1834,7 @@ bool RenderLayerCompositor::requiresCompositingForPosition(RenderObject* rendere
     // Subsequent tests depend on layout. If we can't tell now, just keep things the way they are until layout is done.
     if (!m_inPostLayoutUpdate) {
         m_needsToRecomputeCompositingRequirements = true;
-        return layer->compositedLayerMapping();
+        return layer->hasCompositedLayerMapping();
     }
 
     bool paintsContent = layer->isVisuallyNonEmpty() || layer->hasVisibleDescendant();
@@ -2319,7 +2320,7 @@ static bool isRootmostFixedOrStickyLayer(RenderLayer* layer)
         return false;
 
     for (RenderLayerStackingNode* stackingContainerNode = layer->stackingNode()->ancestorStackingContainerNode(); stackingContainerNode; stackingContainerNode = stackingContainerNode->ancestorStackingContainerNode()) {
-        if (stackingContainerNode->layer()->compositedLayerMapping() && stackingContainerNode->layer()->renderer()->style()->position() == FixedPosition)
+        if (stackingContainerNode->layer()->hasCompositedLayerMapping() && stackingContainerNode->layer()->renderer()->style()->position() == FixedPosition)
             return false;
     }
 
@@ -2349,7 +2350,7 @@ void RenderLayerCompositor::removeViewportConstrainedLayer(RenderLayer* layer)
 
 FixedPositionViewportConstraints RenderLayerCompositor::computeFixedViewportConstraints(RenderLayer* layer) const
 {
-    ASSERT(layer->compositedLayerMapping());
+    ASSERT(layer->hasCompositedLayerMapping());
 
     FrameView* frameView = m_renderView->frameView();
     LayoutRect viewportRect = frameView->viewportConstrainedVisibleContentRect();
@@ -2387,7 +2388,7 @@ FixedPositionViewportConstraints RenderLayerCompositor::computeFixedViewportCons
 
 StickyPositionViewportConstraints RenderLayerCompositor::computeStickyViewportConstraints(RenderLayer* layer) const
 {
-    ASSERT(layer->compositedLayerMapping());
+    ASSERT(layer->hasCompositedLayerMapping());
 
     FrameView* frameView = m_renderView->frameView();
     LayoutRect viewportRect = frameView->viewportConstrainedVisibleContentRect();