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

Source/WebCore/inspector/front-end/treeoutline.js

Index: Source/WebCore/inspector/front-end/treeoutline.js
===================================================================
--- Source/WebCore/inspector/front-end/treeoutline.js	(revision 102898)
+++ Source/WebCore/inspector/front-end/treeoutline.js	(working copy)
@@ -998,7 +998,8 @@
 
 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;
 }