HashMap misuse in ScrollingCoordinator

Source/core/page/scrolling/ScrollingCoordinator.cpp

Index: Source/core/page/scrolling/ScrollingCoordinator.cpp
diff --git a/Source/core/page/scrolling/ScrollingCoordinator.cpp b/Source/core/page/scrolling/ScrollingCoordinator.cpp
index 6147b1228d0c4cef0c9d456665edb1c57156e3e2..1ec95d151c0351b20ed15d051bc58a33fa99d762 100644
--- a/Source/core/page/scrolling/ScrollingCoordinator.cpp
+++ b/Source/core/page/scrolling/ScrollingCoordinator.cpp
@@ -392,12 +392,13 @@ static void makeLayerChildFrameMap(const LocalFrame* currentFrame, LayerFrameMap
     map->clear();
     const FrameTree& tree = currentFrame->tree();
     for (const LocalFrame* child = tree.firstChild(); child; child = child->tree().nextSibling()) {
-        const RenderLayer* containingLayer = child->ownerRenderer()->enclosingLayer();
-        LayerFrameMap::iterator iter = map->find(containingLayer);
-        if (iter == map->end())
-            map->add(containingLayer, Vector<const LocalFrame*>()).storedValue->value.append(child);
-        else
-            iter->value.append(child);
+        if (const RenderLayer* containingLayer = child->ownerRenderer()->enclosingLayer()) {
+            LayerFrameMap::iterator iter = map->find(containingLayer);
+            if (iter == map->end())
+                map->add(containingLayer, Vector<const LocalFrame*>()).storedValue->value.append(child);

[Nico, 2014/03/26 15:48:15]

Should add() ASSERT that the key is non-NULL then?

+            else
+                iter->value.append(child);
+        }
     }
 }