Merge 102757 - Web Inspector: TreeOutline's is broken when li elements have padding-left differen...

Source/WebCore/inspector/front-end/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 980 matching lines @@
         return element;
 
     if (!this.parent || this.parent.root)
         return null;
 
     return this.parent;
 }
 
 TreeElement.prototype.isEventWithinDisclosureTriangle = function(event)
 {
-    const leftPadding = 14;
-    var left = this._listItemNode.totalOffsetLeft() + leftPadding;
+    // FIXME: We should not use getComputedStyle(). For that we need to get rid of using ::before for disclosure triangle. (http://webk.it/74446) 
+    var computedLeftPadding = window.getComputedStyle(this._listItemNode).getPropertyCSSValue("padding-left").getFloatValue(CSSPrimitiveValue.CSS_PX);
+    var left = this._listItemNode.totalOffsetLeft() + computedLeftPadding;
     return event.pageX >= left && event.pageX <= left + this.arrowToggleWidth && this.hasChildren;
 }