DevTools: Fix scrolling of timeline flamechart

third_party/WebKit/Source/devtools/front_end/ui_lazy/ChartViewport.js

 // Copyright 2016 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.VBox}
  */
 WebInspector.ChartViewport = function()
 {
     WebInspector.VBox.call(this, true);
 
     this.contentElement.addEventListener("mousewheel", this._onMouseWheel.bind(this), false);
     this.contentElement.addEventListener("keydown", this._handleZoomPanKeys.bind(this), false);
 
-    WebInspector.installInertialDragHandle(this.contentElement, this._startDragging.bind(this), this._dragging.bind(this), this._endDragging.bind(this), "-webkit-grabbing", null);
-    WebInspector.installDragHandle(this.contentElement, this._startRangeSelection.bind(this), this._rangeSelectionDragging.bind(this), this._endRangeSelection.bind(this), "text", null);
+    /** @private */

[caseq, 2016/10/20 21:33:51]

let's not use it on all privates. perhaps rather fix the compiler?

[alph, 2016/10/20 22:59:37]

Done.

+    this._dragContainer = this.contentElement.createChild("div", "fill");

[caseq, 2016/10/20 21:33:51]

I don't think this is good approach.

[alph, 2016/10/20 22:59:38]

I'd really appreciate if you can suggest anything better. 

+    WebInspector.installInertialDragHandle(this._dragContainer, this._startDragging.bind(this), this._dragging.bind(this), this._endDragging.bind(this), "-webkit-grabbing", null);
+    WebInspector.installDragHandle(this._dragContainer, this._startRangeSelection.bind(this), this._rangeSelectionDragging.bind(this), this._endRangeSelection.bind(this), "text", null);
 
     /** @private */
     this._vScrollElement = this.contentElement.createChild("div", "flame-chart-v-scroll");
     this._vScrollContent = this._vScrollElement.createChild("div");
     this._vScrollElement.addEventListener("scroll", this._onScroll.bind(this), false);
 
     /** @private */
     this._selectionOverlay = this.contentElement.createChild("div", "flame-chart-selection-overlay hidden");
     /** @private */
     this._selectedTimeSpanLabel = this._selectionOverlay.createChild("div", "time-span");
@@ skipping 18 matching lines @@
     {
         return [this._vScrollElement];
     },
 
     /**
      * @private
      */
     _updateScrollBar: function()
     {
         var showScroll = this._totalHeight > this._offsetHeight;
-        if (this._vScrollElement.classList.contains("hidden") === showScroll) {
-            this._vScrollElement.classList.toggle("hidden", !showScroll);
-            this._updateContentElementSize();
-        }
+        if (this._vScrollElement.classList.contains("hidden") !== showScroll)
+            return;
+        this._vScrollElement.classList.toggle("hidden", !showScroll);
+        this._updateContentElementSize();
     },
 
     /**
      * @override
      */
     onResize: function()
     {
         this._updateScrollBar();
         this._updateContentElementSize();
         this.scheduleUpdate();
     },
 
     reset: function()
     {
         this._vScrollElement.scrollTop = 0;
         /** @private */
         this._scrollTop = 0;
         /** @private */
         this._rangeSelectionStart = 0;
         /** @private */
         this._rangeSelectionEnd = 0;
         /** @private */
-        this._scrollTop = 0;
-        /** @private */
         this._isDragging = false;
         /** @private */
         this._dragStartPointX = 0;
         /** @private */
         this._dragStartPointY = 0;
         /** @private */
         this._dragStartScrollTop = 0;
         /** @private */
         this._timeWindowLeft = 0;
         /** @private */
@@ skipping 379 matching lines @@
         this._cancelAnimation();
         this._cancelWindowTimesAnimation = WebInspector.animateFunction(this.element.window(), this._animateWindowTimes.bind(this),
             [{from: this._timeWindowLeft, to: startTime}, {from: this._timeWindowRight, to: endTime}], 5,
             this._animationCompleted.bind(this));
         this._pendingAnimationTimeLeft = startTime;
         this._pendingAnimationTimeRight = endTime;
     },
 
     __proto__: WebInspector.VBox.prototype
 }