DevTools: support importing layer tree from trace snapshots.

Source/devtools/front_end/TimelineTracingView.js

 /*
  * Copyright 2014 The Chromium Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 /**
  * @constructor
  * @implements {WebInspector.TimelineModeView}
  * @implements {WebInspector.FlameChartDelegate}
@@ skipping 87 matching lines @@
             this._delegate.showInDetails("", document.createTextNode(""));
             return;
         }
         var contentHelper = new WebInspector.TimelineDetailsContentHelper(null, null, false);
         contentHelper.appendTextRow(WebInspector.UIString("Name"), record.name);
         contentHelper.appendTextRow(WebInspector.UIString("Category"), record.category);
         contentHelper.appendTextRow(WebInspector.UIString("Start"), Number.millisToString(this._dataProvider._toTimelineTime(record.startTime - this._tracingModel.minimumRecordTime()), true));
         contentHelper.appendTextRow(WebInspector.UIString("Duration"), Number.millisToString(this._dataProvider._toTimelineTime(record.duration), true));
         if (!Object.isEmpty(record.args))
             contentHelper.appendElementRow(WebInspector.UIString("Arguments"), this._formatArguments(record.args));
-
+        function reveal()
+        {
+            WebInspector.Revealer.reveal(new WebInspector.TracingLayerSnapshot(record.args["snapshot"]["active_tree"]["root_layer"]));
+        }
+        if (record.name === "cc::LayerTreeHostImpl") {
+            var link = document.createElement("span");
+            link.classList.add("revealable-link");
+            link.textContent = "show";
+            link.addEventListener("click", reveal, false);
+            contentHelper.appendElementRow(WebInspector.UIString("Layer tree"), link);
+        }
         this._delegate.showInDetails(WebInspector.UIString("Selected Event"), contentHelper.element);
     },
 
     /**
      * @param {!Object} args
      * @return {!Element}
      */
     _formatArguments: function(args)
     {
         var table = document.createElement("table");
@@ skipping 392 matching lines @@
     /**
      * @param {string} string
      * @return {string}
      */
     colorForString: function(string)
     {
         var hash = WebInspector.TraceViewPalette._stringHash(string);
         return this._palette[hash % this._palette.length];
     }
 };