Encapsulate implementation-specific timeline record handling in TimelineUIUtils

Source/devtools/front_end/timeline/TimelineMemoryOverview.js

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 14 matching lines @@
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 /**
  * @constructor
  * @extends {WebInspector.TimelineOverviewBase}
  * @param {!WebInspector.TimelineModel} model
+ * @param {!WebInspector.TimelineUIUtils} uiUtils
  */
-WebInspector.TimelineMemoryOverview = function(model)
+WebInspector.TimelineMemoryOverview = function(model, uiUtils)
 {
     WebInspector.TimelineOverviewBase.call(this, model);
+    this._uiUtils = uiUtils;
     this.element.id = "timeline-overview-memory";
 
     this._heapSizeLabel = this.element.createChild("div", "memory-graph-label");
 }
 
 WebInspector.TimelineMemoryOverview.prototype = {
     resetHeapSizeLabels: function()
     {
         this._heapSizeLabel.textContent = "";
     },
 
     update: function()
     {
         this.resetCanvas();
         var ratio = window.devicePixelRatio;
 
         var records = this._model.records();
         if (!records.length) {
             this.resetHeapSizeLabels();
             return;
         }
 
         var lowerOffset = 3 * ratio;
         var maxUsedHeapSize = 0;
         var minUsedHeapSize = 100000000000;
         var minTime = this._model.minimumRecordTime();
         var maxTime = this._model.maximumRecordTime();
+        var uiUtils = this._uiUtils;
         /**
          * @param {!WebInspector.TimelineModel.Record} record
          */
         function calculateMinMaxSizes(record)
         {
-            var counters = record.counters();
+            var counters = uiUtils.countersForRecord(record);
             if (!counters || !counters.jsHeapSizeUsed)
                 return;
             maxUsedHeapSize = Math.max(maxUsedHeapSize, counters.jsHeapSizeUsed);
             minUsedHeapSize = Math.min(minUsedHeapSize, counters.jsHeapSizeUsed);
         }
         this._model.forAllRecords(calculateMinMaxSizes);
         minUsedHeapSize = Math.min(minUsedHeapSize, maxUsedHeapSize);
 
         var lineWidth = 1;
         var width = this._canvas.width;
         var height = this._canvas.height - lowerOffset;
         var xFactor = width / (maxTime - minTime);
         var yFactor = (height - lineWidth) / Math.max(maxUsedHeapSize - minUsedHeapSize, 1);
 
         var histogram = new Array(width);
 
         /**
          * @param {!WebInspector.TimelineModel.Record} record
          */
         function buildHistogram(record)
         {
-            var counters = record.counters();
+            var counters = uiUtils.countersForRecord(record);
             if (!counters || !counters.jsHeapSizeUsed)
                 return;
             var x = Math.round((record.endTime() - minTime) * xFactor);
             var y = Math.round((counters.jsHeapSizeUsed - minUsedHeapSize) * yFactor);
             histogram[x] = Math.max(histogram[x] || 0, y);
         }
         this._model.forAllRecords(buildHistogram);
 
         var ctx = this._context;
         var heightBeyondView = height + lowerOffset + lineWidth;
@@ skipping 27 matching lines @@
         ctx.fill();
         ctx.lineWidth = lineWidth;
         ctx.strokeStyle = "hsl(220, 90%, 70%)";
         ctx.stroke();
 
         this._heapSizeLabel.textContent = WebInspector.UIString("%s \u2013 %s", Number.bytesToString(minUsedHeapSize), Number.bytesToString(maxUsedHeapSize));
     },
 
     __proto__: WebInspector.TimelineOverviewBase.prototype
 }