Timeline: add preview of painted picture for Paint event

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 18 matching lines @@
      * @return {boolean}
      */
     loadedFromFile: function()
     {
         return this._loadedFromFile;
     },
 
     /**
      * @param {boolean} captureStacks
      * @param {boolean} captureMemory
+     * @param {boolean} capturePictures
      */
-    startRecording: function(captureStacks, captureMemory)
+    startRecording: function(captureStacks, captureMemory, capturePictures)
     {
+        console.assert(!capturePictures, "Legacy timeline does not support capturing pictures");
         this._clientInitiatedRecording = true;
         this.reset();
         var maxStackFrames = captureStacks ? 30 : 0;
         var includeGPUEvents = WebInspector.experimentsSettings.gpuTimeline.isEnabled();
         var liveEvents = [ WebInspector.TimelineModel.RecordType.BeginFrame,
                            WebInspector.TimelineModel.RecordType.DrawFrame,
                            WebInspector.TimelineModel.RecordType.RequestMainThreadFrame,
                            WebInspector.TimelineModel.RecordType.ActivateLayerTree ];
         this._timelineManager.start(maxStackFrames, WebInspector.experimentsSettings.timelineNoLiveUpdate.isEnabled(), liveEvents.join(","), captureMemory, includeGPUEvents, this._fireRecordingStarted.bind(this));
     },
@@ skipping 717 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));
     }
 }