--- a/browser/components/customizableui/PanelMultiView.jsm
+++ b/browser/components/customizableui/PanelMultiView.jsm
@@ -624,16 +624,17 @@ this.PanelMultiView = class extends this
     // The constrained width of subviews may also vary between panels.
     nextPanelView.minMaxWidth = prevPanelView.knownWidth;
 
     if (anchor) {
       viewNode.classList.add("PanelUI-subView");
     }
 
     await this._transitionViews(prevPanelView.node, viewNode, false, anchor);
+    this._viewShown(nextPanelView);
   }
 
   /**
    * Navigates backwards by sliding out the most recent subview.
    */
   goBack() {
     this._goBack().catch(Cu.reportError);
   }
@@ -645,17 +646,19 @@ this.PanelMultiView = class extends this
     }
 
     let prevPanelView = this.openViews[this.openViews.length - 1];
     let nextPanelView = this.openViews[this.openViews.length - 2];
 
     prevPanelView.captureKnownSize();
     await this._transitionViews(prevPanelView.node, nextPanelView.node, true);
 
-    this.openViews.pop();
+    this._closeLatestView();
+
+    this._viewShown(nextPanelView);
   }
 
   /**
    * Prepares the main view before showing the panel.
    */
   async showMainView() {
     if (!this.node || !this._mainViewId) {
       return false;
@@ -670,16 +673,17 @@ this.PanelMultiView = class extends this
     // reset all the properties that may be set on a subview.
     nextPanelView.mainview = true;
     nextPanelView.headerText = "";
     nextPanelView.minMaxWidth = 0;
 
     await this._cleanupTransitionPhase();
     this.hideAllViewsExcept(nextPanelView);
 
+    this._viewShown(nextPanelView);
     return true;
   }
 
   /**
    * Ensures that all the panelviews, that are currently part of this instance,
    * are hidden, except one specifically.
    *
    * @param {panelview} [nextPanelView]
@@ -722,26 +726,48 @@ this.PanelMultiView = class extends this
     // point the ViewHiding event has already been dispatched for all of them.
     if (!this.openViews.length) {
       return false;
     }
 
     // Check if the event requested cancellation but the panel is still open.
     if (canceled) {
       // Handlers for ViewShowing can't know if a different handler requested
-      // cancellation, so we dispatch an event to give a chance to clean up.
-      panelView.dispatchCustomEvent("ViewHiding");
-      this.openViews.pop();
+      // cancellation, so this will dispatch a ViewHiding event to give a chance
+      // to clean up.
+      this._closeLatestView();
       return false;
     }
 
     return true;
   }
 
   /**
+   * Raises the ViewShown event if the specified view is still open.
+   */
+  _viewShown(panelView) {
+    if (panelView.node.panelMultiView == this.node) {
+      panelView.dispatchCustomEvent("ViewShown");
+    }
+  }
+
+  /**
+   * Closes the most recent PanelView and raises the ViewHiding event.
+   *
+   * @note The ViewHiding event is not cancelable and should probably be renamed
+   *       to ViewHidden or ViewClosed instead, see bug 1438507.
+   */
+  _closeLatestView() {
+    let panelView = this.openViews.pop();
+    panelView.clearNavigation();
+    panelView.dispatchCustomEvent("ViewHiding");
+    panelView.node.panelMultiView = null;
+  }
+
+  /**
    * Apply a transition to 'slide' from the currently active view to the next
    * one.
    * Sliding the next subview in means that the previous panelview stays where it
    * is and the active panelview slides in from the left in LTR mode, right in
    * RTL mode.
    *
    * @param {panelview} previousViewNode Node that is currently shown as active,
    *                                     but is about to be transitioned away.
@@ -919,25 +945,22 @@ this.PanelMultiView = class extends this
     if (!details || !this.node)
       return;
 
     let {phase, previousViewNode, viewNode, reverse, resolve, listener, cancelListener, anchor} = details;
     if (details == this._transitionDetails)
       this._transitionDetails = null;
 
     let nextPanelView = PanelView.forNode(viewNode);
-    let prevPanelView = PanelView.forNode(previousViewNode);
 
     // Do the things we _always_ need to do whenever the transition ends or is
     // interrupted.
     this.hideAllViewsExcept(nextPanelView);
     previousViewNode.removeAttribute("in-transition");
     viewNode.removeAttribute("in-transition");
-    if (reverse)
-      prevPanelView.clearNavigation();
 
     if (anchor)
       anchor.removeAttribute("open");
 
     if (phase >= TRANSITION_PHASES.START) {
       this._panel.removeAttribute("width");
       this._panel.removeAttribute("height");
       // Myeah, panel layout auto-resizing is a funky thing. We'll wait
@@ -1062,23 +1085,24 @@ this.PanelMultiView = class extends this
         // description elements it contains.
         PanelView.forNode(this._mainView).descriptionHeightWorkaround();
         break;
       case "popuphidden": {
         // WebExtensions consumers can hide the popup from viewshowing, or
         // mid-transition, which disrupts our state:
         this._transitioning = false;
         this.node.removeAttribute("panelopen");
-        // Raise the ViewHiding event for the current view.
         this._cleanupTransitionPhase();
         this.hideAllViewsExcept(null);
         this.window.removeEventListener("keydown", this);
         this._panel.removeEventListener("mousemove", this);
-        this.openViews.forEach(panelView => panelView.clearNavigation());
-        this.openViews = [];
+        // Raise ViewHiding events for open views in reverse order.
+        while (this.openViews.length) {
+          this._closeLatestView();
+        }
 
         // Clear the main view size caches. The dimensions could be different
         // when the popup is opened again, e.g. through touch mode sizing.
         this._viewContainer.style.removeProperty("min-height");
         this._viewStack.style.removeProperty("max-height");
         this._viewContainer.style.removeProperty("width");
         this._viewContainer.style.removeProperty("height");
 
@@ -1107,20 +1131,18 @@ this.PanelView = class extends this.Asso
     }
   }
 
   set current(value) {
     if (value) {
       if (!this.node.hasAttribute("current")) {
         this.node.setAttribute("current", true);
         this.descriptionHeightWorkaround();
-        this.dispatchCustomEvent("ViewShown");
       }
-    } else if (this.node.hasAttribute("current")) {
-      this.dispatchCustomEvent("ViewHiding");
+    } else {
       this.node.removeAttribute("current");
     }
   }
 
   /**
    * Constrains the width of this view using the "min-width" and "max-width"
    * styles. Setting this to zero removes the constraints.
    */

--- a/browser/components/places/content/browserPlacesViews.js
+++ b/browser/components/places/content/browserPlacesViews.js
@@ -2112,24 +2112,16 @@ this.PlacesPanelview = class extends Pla
   }
 
   get events() {
     if (this._events)
       return this._events;
     return this._events = ["click", "command", "dragend", "dragstart", "ViewHiding", "ViewShown"];
   }
 
-  get panel() {
-    return this.panelMultiView.parentNode;
-  }
-
-  get panelMultiView() {
-    return this._viewElt.panelMultiView;
-  }
-
   handleEvent(event) {
     switch (event.type) {
       case "click":
         // For middle clicks, fall through to the command handler.
         if (event.button != 1) {
           break;
         }
       case "command":
@@ -2191,16 +2183,17 @@ this.PlacesPanelview = class extends Pla
 
     this._controller.setDataTransfer(event);
     event.stopPropagation();
   }
 
   uninit(event) {
     this._removeEventListeners(this.panelMultiView, this.events);
     this._removeEventListeners(window, ["unload"]);
+    delete this.panelMultiView;
     super.uninit(event);
   }
 
   _createDOMNodeForPlacesNode(placesNode) {
     this._domNodes.delete(placesNode);
 
     let element;
     let type = placesNode.type;
@@ -2271,16 +2264,17 @@ this.PlacesPanelview = class extends Pla
     }
   }
 
   _onPopupShowing(event) {
     // If the event came from the root element, this is the first time
     // we ever get here.
     if (event.originalTarget == this._rootElt) {
       // Start listening for events from all panels inside the panelmultiview.
+      this.panelMultiView = this._viewElt.panelMultiView;
       this._addEventListeners(this.panelMultiView, this.events);
     }
     super._onPopupShowing(event);
   }
 
   _onViewShown(event) {
     if (event.originalTarget != this._viewElt)
       return;