Merge 159961 "Defer the real work in updateCompositingLayers unt..."

Source/core/inspector/InspectorLayerTreeAgent.cpp

Index: Source/core/inspector/InspectorLayerTreeAgent.cpp
===================================================================
--- Source/core/inspector/InspectorLayerTreeAgent.cpp	(revision 159992)
+++ Source/core/inspector/InspectorLayerTreeAgent.cpp	(working copy)
@@ -181,6 +181,8 @@
         *errorString = "Not in the compositing mode";
         return;
     }
+    // FIXME: when inspector layer access is made asynchronous, this will probably need to be changed.
+    compositor->updateCompositingLayers(CompositingUpdateFinishAllDeferredWork);
     if (!nodeId) {
         buildLayerIdToNodeIdMap(errorString, compositor->rootRenderLayer(), layerIdToNodeIdMap);
         gatherGraphicsLayers(compositor->rootGraphicsLayer(), layerIdToNodeIdMap, layers);
@@ -197,6 +199,7 @@
         return;
     }
     RenderLayer* enclosingLayer = renderer->enclosingLayer();
+    ASSERT(enclosingLayer->enclosingCompositingLayer());
     GraphicsLayer* enclosingGraphicsLayer = enclosingLayer->enclosingCompositingLayer()->compositedLayerMapping()->childForSuperlayers();
     buildLayerIdToNodeIdMap(errorString, enclosingLayer, layerIdToNodeIdMap);
     gatherGraphicsLayers(enclosingGraphicsLayer, layerIdToNodeIdMap, layers);