Change layerTreeAsText to default to layer lists.

third_party/WebKit/LayoutTests/compositing/overflow/overflow-scroll-background-opaque-to-transparent.html

 <script src="../../resources/run-after-layout-and-paint.js"></script>
+<script src="resources/composited-scroll.js"></script>
 <script>
     if (window.internals)
         internals.runtimeFlags.compositeOpaqueScrollersEnabled = true;
 
     if (window.testRunner) {
         testRunner.dumpAsTextWithPixelResults();
         testRunner.waitUntilDone();
     }
 
-    function hasOpaqueCompositedScrollingContentsLayer(layer) {
-        if (layer.name == "Scrolling Contents Layer")
-            return layer.contentsOpaque;
-        if (layer.children) {
-            for (var i = 0; i < layer.children.length; i++) {
-                if (hasOpaqueCompositedScrollingContentsLayer(layer.children[i]))
-                    return true;
-            }
-        }
-        return false;
-    }
-
-    function hasCompositedScrollingContentsLayer(layer) {
-        if (layer.name == "Scrolling Contents Layer")
-            return true;
-        if (layer.children) {
-            for (var i = 0; i < layer.children.length; i++) {
-                if (hasCompositedScrollingContentsLayer(layer.children[i]))
-                    return true;
-            }
-        }
-        return false;
-    }
-
     onload = function() {
         if (!window.testRunner || !window.internals)
             return;
 
         var result = "Should have opaque composited scrolling contents layer: ";
         if (hasOpaqueCompositedScrollingContentsLayer(JSON.parse(window.internals.layerTreeAsText(document))))
             result += "Pass.\n";
         else
             result += "Fail.\n";
         document.getElementById("test-1-output").innerHTML = result;
 
         scrollerElement = document.getElementById("scroller");
         scrollerElement.style.background = "transparent local content-box";
 
         runAfterLayoutAndPaint(function() {
             var result = "Should not have opaque composited scrolling contents layer: ";
-            if (!hasCompositedScrollingContentsLayer(JSON.parse(window.internals.layerTreeAsText(document))))
+            if (!isUsingCompositedScrolling(JSON.parse(window.internals.layerTreeAsText(document))))
                 result += "Pass.\n";
             else
                 result += "Fail.\n";
             document.getElementById("test-2-output").innerHTML = result;
             runAfterLayoutAndPaint(function() { testRunner.notifyDone(); });
         });
     }
 </script>
 <style>
 #scroller {
     background: red local content-box;
     border: 10px solid rgba(0, 255, 0, 0.5);
     overflow: scroll;
     width: 200px;
     height: 200px;
 }
 .spacer {
     height: 300px;
 }
 </style>
 <div id="scroller"><div class="spacer"></div></div>
 <p>Scroller background should be white</p>
 <p id="test-1-output"></p>
 <p id="test-2-output"></p>