DevTools: Show scrollbars on a small FilteredListWidget

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 {
   /**
    * @param {!Document} document
    * @param {boolean} dimmed
    * @param {boolean} blockPointerEvents
    * @param {function(!Event)} onClickOutside
@@ skipping 13 matching lines @@
     this._visible = false;
     /** @type {?UI.Size} */
     this._maxSize = null;
     /** @type {?number} */
     this._positionX = null;
     /** @type {?number} */
     this._positionY = null;
     /** @type {?AnchorBox} */
     this._anchorBox = null;
     this._anchorBehavior = UI.GlassPane.AnchorBehavior.PreferTop;
+    this._fixedHeight = true;
   }
 
   /**
    * @param {?UI.Size} size
    */
   setMaxContentSize(size) {
     this._maxSize = size;
     this._positionContent();
   }
 
   /**
+   * @param {boolean} fixedHeight
+   */
+  setFixedHeight(fixedHeight) {
+    this._fixedHeight = fixedHeight;
+  }
+
+  /**
    * @param {?number} x
    * @param {?number} y
    * Position is relative to root element.
    */
   setContentPosition(x, y) {
     this._positionX = x;
     this._positionY = y;
     this._positionContent();
   }
 
@@ skipping 99 matching lines @@
         }
       }
     } else {
       positionX = this._positionX !== null ? this._positionX : (containerWidth - width) / 2;
       positionY = this._positionY !== null ? this._positionY : (containerHeight - height) / 2;
       width = Math.min(width, containerWidth - positionX - gutterSize);
       height = Math.min(height, containerHeight - positionY - gutterSize);
     }
 
     this.contentElement.style.width = width + 'px';
-    this.contentElement.style.height = height + 'px';
+    if (this._fixedHeight)
+      this.contentElement.style.height = height + 'px';
+    else
+      this.contentElement.style.maxHeight = height + 'px';
     this.contentElement.positionAt(positionX, positionY, container);
   }
 
   /**
    * @param {!Element} element
    */
   static setContainer(element) {
     UI.GlassPane._containers.set(/** @type {!Document} */ (element.ownerDocument), element);
     UI.GlassPane.containerMoved(element);
   }
@@ skipping 24 matching lines @@
   PreferTop: Symbol('PreferTop'),
   PreferBottom: Symbol('PreferBottom'),
   PreferLeft: Symbol('PreferLeft'),
   PreferRight: Symbol('PreferRight'),
 };
 
 /** @type {!Map<!Document, !Element>} */
 UI.GlassPane._containers = new Map();
 /** @type {!Set<!UI.GlassPane>} */
 UI.GlassPane._panes = new Set();