Correctly calculate highlighted quad for tracing based timeline events

Source/devtools/front_end/timeline/TimelineModelImpl.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
  * @extends {WebInspector.TimelineModel}
  * @param {!WebInspector.TimelineManager} timelineManager
  */
 WebInspector.TimelineModelImpl = function(timelineManager)
@@ skipping 461 matching lines @@
 
     /**
      * @return {string}
      */
     type: function()
     {
         return this._record.type;
     },
 
     /**
+     * @return {?Object}
+     */
+    highlightQuad: function()
+    {
+        var quad = null;
+        var recordTypes = WebInspector.TimelineModel.RecordType;
+        switch(this.type()) {
+        case recordTypes.Layout:
+            quad = this.data().root;
+            break;
+        case recordTypes.Paint:
+            quad = this.data().clip;
+            break;
+        default:
+            break;
+        }
+        return quad;
+    },
+
+    /**
      * @return {string}
      */
     frameId: function()
     {
         return this._record.frameId || "";
     },
 
     /**
      * @return {?Array.<!ConsoleAgent.CallFrame>}
      */
@@ skipping 257 matching lines @@
                 break;
             length += itemLength;
             data.push(item);
             ++this._recordIndex;
         }
         if (this._recordIndex === this._payloads.length)
             data.push(data.pop() + "]");
         stream.write(data.join(separator), this._writeNextChunk.bind(this));
     }
 }