[Devtools] Fix left margin for selection element

third_party/WebKit/Source/devtools/front_end/ui/treeoutline.js

 /*
  * Copyright (C) 2007 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
@@ skipping 301 matching lines @@
    * @param {(string|!Node)=} title
    * @param {boolean=} expandable
    */
   constructor(title, expandable) {
     /** @type {?UI.TreeOutline} */
     this.treeOutline = null;
     this.parent = null;
     this.previousSibling = null;
     this.nextSibling = null;
 
+    // Adjust based on your CSS, if modified from treeoutline.css
+    // Check the padding-left for the li element
+    this.paddingSize = 12;

[dgozman, 2017/01/13 01:53:42]

Default should be zero preserving -10000px we have now, or else this will
regress some trees.

[aboxhall, 2017/01/13 02:22:03]

Done.

+
     this._listItemNode = createElement('li');
     this._titleElement = this._listItemNode.createChild('span', 'tree-element-title');
     this._listItemNode.treeElement = this;
     if (title)
       this.title = title;
     this._listItemNode.addEventListener('mousedown', this._handleMouseDown.bind(this), false);
     this._listItemNode.addEventListener('click', this._treeElementToggled.bind(this), false);
     this._listItemNode.addEventListener('dblclick', this._handleDoubleClick.bind(this), false);
 
     this._childrenListNode = createElement('ol');
@@ skipping 413 matching lines @@
     this._childrenListNode.classList.toggle('hidden', x);
   }
 
   invalidateChildren() {
     if (this._children) {
       this.removeChildren();
       this._children = null;
     }
   }
 
+  /**
+   * @return {number}
+   */
+  computeLeftIndent() {
+    var treeElement = this.parent;
+    var depth = 0;
+    while (treeElement !== null) {
+      depth++;
+      treeElement = treeElement.parent;
+    }
+
+    return this.paddingSize * (depth - 1) + 4;
+  }
+
   _ensureSelection() {
     if (!this.treeOutline || !this.treeOutline._renderSelection)
       return;
     if (!this._selectionElement)
       this._selectionElement = createElementWithClass('div', 'selection fill');
+    this._selectionElement.style.setProperty('margin-left', (-this.computeLeftIndent()) + 'px');
     this._listItemNode.insertBefore(this._selectionElement, this.listItemElement.firstChild);
   }
 
   /**
    * @param {!Event} event
    */
   _treeElementToggled(event) {
     var element = event.currentTarget;
     if (element.treeElement !== this || element.hasSelection())
       return;
@@ skipping 407 matching lines @@
     var paddingLeftValue = window.getComputedStyle(this._listItemNode).paddingLeft;
     console.assert(paddingLeftValue.endsWith('px'));
     var computedLeftPadding = parseFloat(paddingLeftValue);
     var left = this._listItemNode.totalOffsetLeft() + computedLeftPadding;
     return event.pageX >= left && event.pageX <= left + UI.TreeElement._ArrowToggleWidth && this._expandable;
   }
 };
 
 /** @const */
 UI.TreeElement._ArrowToggleWidth = 10;