[DevTools] Make UI.GlassPane position contentElement for different overlay controls.

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

 /*
  * Copyright (C) 2009 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 147 matching lines @@
     const arrowHeight = this._hasNoPadding ? 8 : 15;
     const arrowOffset = 10;
     const borderRadius = 4;
     const arrowRadius = 6;
     preferredWidth = preferredWidth || this._preferredWidth;
     preferredHeight = preferredHeight || this._preferredHeight;
 
     // Skinny tooltips are not pretty, their arrow location is not nice.
     preferredWidth = Math.max(preferredWidth, 50);
     // Position relative to main DevTools element.
-    const container = UI.Dialog.modalHostView().element;
+    const container = UI.GlassPane.container(/** @type {!Document} */ (this._containerElement.ownerDocument));
     const totalWidth = container.offsetWidth;
     const totalHeight = container.offsetHeight;
 
     var anchorBox = anchorElement instanceof AnchorBox ? anchorElement : anchorElement.boxInWindow(window);
     anchorBox = anchorBox.relativeToElement(container);
     var newElementPosition = {x: 0, y: 0, width: preferredWidth + scrollerWidth, height: preferredHeight};
 
     var verticalAlignment;
     var roomAbove = anchorBox.y;
     var roomBelow = totalHeight - anchorBox.y - anchorBox.height;
@@ skipping 225 matching lines @@
       this._resetHoverTimer();
     }
   }
 };
 
 /** @enum {string} */
 UI.Popover.Orientation = {
   Top: 'top',
   Bottom: 'bottom'
 };