Change layerTreeAsText to default to layer lists.

third_party/WebKit/LayoutTests/compositing/overflow/resources/composited-scroll.js

 function isUsingCompositedScrolling(layers) {
     var foundScrollingContentsLayer = false;
     layers["layers"].forEach(function(layer) {
         if (layer.name == "Scrolling Contents Layer")
             foundScrollingContentsLayer = true;
     });
 
     return foundScrollingContentsLayer;
 }
+
+function hasOpaqueCompositedScrollingContentsLayer(layers) {
+    var found = false;
+    layers["layers"].forEach(function(layer) {
+      if (layer.name == "Scrolling Contents Layer")
+        found = found || layer.contentsOpaque;
+    });
+    return found;
+}
+
+function hasNotOpaqueCompositedScrollingContentsLayer(layers) {
+    var found = false;
+    layers["layers"].forEach(function(layer) {
+      if (layer.name == "Scrolling Contents Layer")
+        found = found || !layer.contentsOpaque;
+    });
+    return found;
+}