[Devtools] Change logic of DataGrid's padding-left for grouping

third_party/WebKit/Source/devtools/front_end/data_grid/DataGrid.js

 /*
  * Copyright (C) 2008 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *        notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *        notice, this list of conditions and the following disclaimer in the
@@ skipping 1246 matching lines @@
     /** @type {?DataGrid.DataGrid} */
     this.dataGrid = null;
     /** @type {?NODE_TYPE} */
     this._parent = null;
     /** @type {?NODE_TYPE} */
     this.previousSibling = null;
     /** @type {?NODE_TYPE} */
     this.nextSibling = null;
     /** @type {number} */
     this.disclosureToggleWidth = 10;
+    /** @type {?Element} */
+    this._disclosureCell = null;
 
     /** @type {boolean} */
     this.selectable = true;
 
     /** @type {boolean} */
     this._isRoot = false;
   }
 
   /**
    * @return {!Element}
    */
   element() {
     if (!this._element) {
       var element = this.createElement();
       this.createCells(element);
     }
     return /** @type {!Element} */ (this._element);
   }
 
   /**
+   * @return {?Element}
+   */
+  disclosureCell() {
+    return this._disclosureCell;
+  }
+
+  /**
    * @protected
    * @return {!Element}
    */
   createElement() {
     this._element = createElement('tr');
     this._element._dataGridNode = this;
 
     if (this._hasChildren)
       this._element.classList.add('parent');
     if (this.expanded)
@@ skipping 266 matching lines @@
    */
   createTD(columnId) {
     var cell = this._createTDWithClass(columnId + '-column');
     cell[DataGrid.DataGrid._columnIdSymbol] = columnId;
 
     var alignment = this.dataGrid._columns[columnId].align;
     if (alignment)
       cell.classList.add(alignment);
 
     if (columnId === this.dataGrid.disclosureColumnId) {
+      this._disclosureCell = cell;
       cell.classList.add('disclosure');
-      if (this.leftPadding)
-        cell.style.setProperty('padding-left', this.leftPadding + 'px');
     }
 
     return cell;
   }
 
   /**
    * @param {string} columnId
    * @return {!Element}
    */
   createCell(columnId) {
@@ skipping 344 matching lines @@
       return false;
 
     var left = cell.totalOffsetLeft() + this.leftPadding;
     return event.pageX >= left && event.pageX <= left + this.disclosureToggleWidth;
   }
 
   _attach() {
     if (!this.dataGrid || this._attached)
       return;
 
+    var leftPadding = this.leftPadding;
+    if (leftPadding && this._disclosureCell)
+      this._disclosureCell.style.setProperty('padding-left', leftPadding + 'px');
+
     this._attached = true;
 
     var previousNode = this.traversePreviousNode(true, true);
     var previousElement = previousNode ? previousNode.element() : this.dataGrid._topFillerRow;
     this.dataGrid.dataTableBody.insertBefore(this.element(), previousElement.nextSibling);
 
     if (this.expanded) {
       for (var i = 0; i < this.children.length; ++i)
         this.children[i]._attach();
     }
@@ skipping 99 matching lines @@
   /**
    * @override
    */
   detachChildWidgets() {
     super.detachChildWidgets();
     for (var dataGrid of this._dataGrids)
       this.element.removeChild(dataGrid.element);
     this._dataGrids = [];
   }
 };