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

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

 // Copyright (c) 2015 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.
 /**
  * @unrestricted
  */
 UI.Tooltip = class {
   /**
    * @param {!Document} doc
    */
@@ skipping 95 matching lines @@
     // Reposition to ensure text doesn't overflow unnecessarily.
     this._tooltipElement.positionAt(0, 0);
 
     // Show tooltip instantly if a tooltip was shown recently.
     var now = Date.now();
     var instant = (this._tooltipLastClosed && now - this._tooltipLastClosed < UI.Tooltip.Timing.InstantThreshold);
     this._tooltipElement.classList.toggle('instant', instant);
     this._tooltipLastOpened = instant ? now : now + UI.Tooltip.Timing.OpeningDelay;
 
     // Get container element.
-    var container = UI.Dialog.modalHostView().element;
+    var container = UI.GlassPane.container(/** @type {!Document} */ (anchorElement.ownerDocument));
     // Position tooltip based on the anchor element.
     var containerBox = container.boxInWindow(this.element.window());
     var anchorBox = this._anchorElement.boxInWindow(this.element.window());
     const anchorOffset = 2;
     const pageMargin = 2;
     var cursorOffset = 10;
     this._tooltipElement.classList.toggle('tooltip-breakword', !this._tooltipElement.textContent.match('\\s'));
     this._tooltipElement.style.maxWidth = (containerBox.width - pageMargin * 2) + 'px';
     this._tooltipElement.style.maxHeight = '';
     var tooltipWidth = this._tooltipElement.offsetWidth;
@@ skipping 61 matching lines @@
   },
 
   /**
    * @param {!Element|string} x
    * @this {!Element}
    */
   set: function(x) {
     UI.Tooltip.install(this, x);
   }
 });