[DevTools] Adjust popover arrow position.

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

 // Copyright 2017 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.
 
 UI.GlassPane = class {
   constructor() {
     this._widget = new UI.Widget(true);
     this._widget.markAsRoot();
     this.element = this._widget.element;
     this.contentElement = this._widget.contentElement;
@@ skipping 134 matching lines @@
       return;
     if (this.contentElement.isSelfOrAncestor(/** @type {?Node} */ (event.deepElementFromPoint())))
       return;
     this._onClickOutsideCallback.call(null, event);
   }
 
   _positionContent() {
     if (!this.isShowing())
       return;
 
-    var gutterSize = this._showArrow ? 6 : 3;
+    var gutterSize = this._showArrow ? 8 : 3;
     var scrollbarSize = 14;
     var arrowSize = 10;
 
     var container = UI.GlassPane._containers.get(/** @type {!Document} */ (this.element.ownerDocument));
     if (this._sizeBehavior === UI.GlassPane.SizeBehavior.MeasureContent) {
       this.contentElement.positionAt(0, 0);
       this.contentElement.style.width = '';
       this.contentElement.style.maxWidth = '';
       this.contentElement.style.height = '';
       this.contentElement.style.maxHeight = '';
@@ skipping 200 matching lines @@
 UI.GlassPane.SizeBehavior = {
   SetExactSize: Symbol('SetExactSize'),
   SetExactWidthMaxHeight: Symbol('SetExactWidthMaxHeight'),
   MeasureContent: Symbol('MeasureContent')
 };
 
 /** @type {!Map<!Document, !Element>} */
 UI.GlassPane._containers = new Map();
 /** @type {!Set<!UI.GlassPane>} */
 UI.GlassPane._panes = new Set();