DevTools: fix popover's account for scrollbar size when measuring content

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 166 matching lines @@
     var width = containerWidth - gutterSize * 2;
     var height = containerHeight - gutterSize * 2;
     var positionX = gutterSize;
     var positionY = gutterSize;
 
     if (this._maxSize) {
       width = Math.min(width, this._maxSize.width);
       height = Math.min(height, this._maxSize.height);
     }
 
-    var measuredWidth = 0;
-    var measuredHeight = 0;
     if (this._sizeBehavior === UI.GlassPane.SizeBehavior.MeasureContent) {
-      measuredWidth = this.contentElement.offsetWidth;
-      measuredHeight = this.contentElement.offsetHeight;
-      width = Math.min(width, measuredWidth);
-      height = Math.min(height, measuredHeight);
+      var measuredWidth = this.contentElement.offsetWidth;
+      var measuredHeight = this.contentElement.offsetHeight;
+      var widthOverflow = height < measuredHeight ? scrollbarSize : 0;
+      var heightOverflow = width < measuredWidth ? scrollbarSize : 0;
+      width = Math.min(width, measuredWidth + widthOverflow);
+      height = Math.min(height, measuredHeight + heightOverflow);
     }
 
     if (this._anchorBox) {
       var anchorBox = this._anchorBox.relativeToElement(container);
       var behavior = this._anchorBehavior;
       this._arrowElement.classList.remove('arrow-none', 'arrow-top', 'arrow-bottom', 'arrow-left', 'arrow-right');
 
       if (behavior === UI.GlassPane.AnchorBehavior.PreferTop || behavior === UI.GlassPane.AnchorBehavior.PreferBottom) {
         var top = anchorBox.y - 2 * gutterSize;
         var bottom = containerHeight - anchorBox.y - anchorBox.height - 2 * gutterSize;
         if (behavior === UI.GlassPane.AnchorBehavior.PreferTop && top < height && bottom > top)
           behavior = UI.GlassPane.AnchorBehavior.PreferBottom;
         if (behavior === UI.GlassPane.AnchorBehavior.PreferBottom && bottom < height && top > bottom)
           behavior = UI.GlassPane.AnchorBehavior.PreferTop;
 
         var arrowY;
         var enoughHeight = true;
         if (behavior === UI.GlassPane.AnchorBehavior.PreferTop) {
           positionY = Math.max(gutterSize, anchorBox.y - height - gutterSize);
           var spaceTop = anchorBox.y - positionY - gutterSize;
           if (this._sizeBehavior === UI.GlassPane.SizeBehavior.MeasureContent) {
-            if (height < measuredHeight)
-              width += scrollbarSize;
             if (height > spaceTop) {
               this._arrowElement.classList.add('arrow-none');
               enoughHeight = false;
             }
           } else {
             height = Math.min(height, spaceTop);
           }
           this._arrowElement.setIconType('mediumicon-arrow-bottom');
           this._arrowElement.classList.add('arrow-bottom');
           arrowY = anchorBox.y - gutterSize;
         } else {
           positionY = anchorBox.y + anchorBox.height + gutterSize;
           var spaceBottom = containerHeight - positionY - gutterSize;
           if (this._sizeBehavior === UI.GlassPane.SizeBehavior.MeasureContent) {
-            if (height < measuredHeight)
-              width += scrollbarSize;
             if (height > spaceBottom) {
               this._arrowElement.classList.add('arrow-none');
               positionY = containerHeight - gutterSize - height;
               enoughHeight = false;
             }
           } else {
             height = Math.min(height, spaceBottom);
           }
           this._arrowElement.setIconType('mediumicon-arrow-top');
           this._arrowElement.classList.add('arrow-top');
@@ skipping 20 matching lines @@
           behavior = UI.GlassPane.AnchorBehavior.PreferRight;
         if (behavior === UI.GlassPane.AnchorBehavior.PreferRight && right < width && left > right)
           behavior = UI.GlassPane.AnchorBehavior.PreferLeft;
 
         var arrowX;
         var enoughWidth = true;
         if (behavior === UI.GlassPane.AnchorBehavior.PreferLeft) {
           positionX = Math.max(gutterSize, anchorBox.x - width - gutterSize);
           var spaceLeft = anchorBox.x - positionX - gutterSize;
           if (this._sizeBehavior === UI.GlassPane.SizeBehavior.MeasureContent) {
-            if (width < measuredWidth)
-              height += scrollbarSize;
             if (width > spaceLeft) {
               this._arrowElement.classList.add('arrow-none');
               enoughWidth = false;
             }
           } else {
             width = Math.min(width, spaceLeft);
           }
           this._arrowElement.setIconType('mediumicon-arrow-right');
           this._arrowElement.classList.add('arrow-right');
           arrowX = anchorBox.x - gutterSize;
         } else {
           positionX = anchorBox.x + anchorBox.width + gutterSize;
           var spaceRight = containerWidth - positionX - gutterSize;
           if (this._sizeBehavior === UI.GlassPane.SizeBehavior.MeasureContent) {
-            if (width < measuredWidth)
-              height += scrollbarSize;
             if (width > spaceRight) {
               this._arrowElement.classList.add('arrow-none');
               positionX = containerWidth - gutterSize - width;
               enoughWidth = false;
             }
           } else {
             width = Math.min(width, spaceRight);
           }
           this._arrowElement.setIconType('mediumicon-arrow-left');
           this._arrowElement.classList.add('arrow-left');
@@ skipping 93 matching lines @@
 UI.GlassPane.MarginBehavior = {
   Arrow: Symbol('Arrow'),
   DefaultMargin: Symbol('DefaultMargin'),
   NoMargin: Symbol('NoMargin')
 };
 
 /** @type {!Map<!Document, !Element>} */
 UI.GlassPane._containers = new Map();
 /** @type {!Set<!UI.GlassPane>} */
 UI.GlassPane._panes = new Set();