--- a/browser/base/content/appmenu-viewcache.inc.xhtml
+++ b/browser/base/content/appmenu-viewcache.inc.xhtml
@@ -1,28 +1,26 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 <html:template id="appMenu-viewCache">
-  <panelview id="appMenu-mainView" class="PanelUI-subView"
-             descriptionheightworkaround="true">
+  <panelview id="appMenu-mainView" class="PanelUI-subView">
     <vbox class="panel-subview-body">
       <toolbarbutton id="appMenu-whatsnew-button"
                      class="subviewbutton subviewbutton-iconic subviewbutton-nav"
                      hidden="true"
                      closemenu="none"
                      oncommand="PanelUI.showSubView('PanelUI-whatsNew', this)"/>
     </vbox>
   </panelview>
 
   <!-- This is a placeholder app menu which should be replaced with the "real"
        Proton app menu before the Proton pref starts getting enabled. -->
   <panelview id="appMenu-protonMainView" class="PanelUI-subView"
-             descriptionheightworkaround="true"
              lockpanelvertical="true">
     <vbox class="panel-subview-body">
       <vbox id="appMenu-proton-addon-banners"/>
       <toolbarbutton id="appMenu-proton-update-banner" class="panel-banner-item subviewbutton"
                      oncommand="PanelUI._onBannerItemSelected(event)"
                      wrap="true"
                      hidden="true"/>
       <toolbaritem id="appMenu-fxa-status2"
@@ -243,17 +241,17 @@
     <toolbarseparator/>
     <toolbarbutton id="panelMenu_showAllBookmarks"
                    data-l10n-id="bookmarks-manage-bookmarks"
                    class="subviewbutton panel-subview-footer-button"
                    command="Browser:ShowAllBookmarks"
                    />
   </panelview>
 
-  <panelview id="PanelUI-profiler" flex="1" descriptionheightworkaround="true">
+  <panelview id="PanelUI-profiler" flex="1">
     <vbox id="PanelUI-profiler-container">
       <vbox id="PanelUI-profiler-header" animationready="false">
         <hbox id="PanelUI-profiler-header-bar">
           <label flex="1" data-l10n-id="profiler-popup-title" />
           <vbox class="PanelUI-profiler-toolbarbutton-container">
             <toolbarbutton id="PanelUI-profiler-info-button"
                           class="panel-info-button"
                           closemenu="none"
@@ -340,18 +338,17 @@
             <label data-l10n-id="profiler-popup-capture-shortcut"
                    class="PanelUI-profiler-shortcut" />
           </vbox>
         </hbox>
       </vbox>
     </vbox>
   </panelview>
 
-  <panelview id="PanelUI-panicView" flex="1"
-             descriptionheightworkaround="true">
+  <panelview id="PanelUI-panicView" flex="1">
     <vbox class="panel-subview-body">
       <hbox id="PanelUI-panic-timeframe">
         <image id="PanelUI-panic-timeframe-icon" alt=""/>
         <vbox flex="1">
           <description data-l10n-id="panic-main-timeframe-desc" id="PanelUI-panic-mainDesc"></description>
           <radiogroup id="PanelUI-panic-timeSpan" aria-labelledby="PanelUI-panic-mainDesc" closemenu="none">
             <radio id="PanelUI-panic-5min" data-l10n-id="panic-button-5min" selected="true"
                   value="5" class="subviewradio"/>
@@ -407,18 +404,17 @@
              flex="1" class="PanelUI-subView"
              remote="true"
              neverhidden="true"
              closemenu="none">
     <vbox class="PanelUI-savetopocket-container">
     </vbox>
   </panelview>
 
-  <panelview id="PanelUI-remotetabs" flex="1" class="PanelUI-subView"
-             descriptionheightworkaround="true">
+  <panelview id="PanelUI-remotetabs" flex="1" class="PanelUI-subView">
     <vbox class="panel-subview-body">
       <!-- this widget has 3 boxes in the body, but only 1 is ever visible -->
       <!-- When Sync is ready to sync -->
       <vbox id="PanelUI-remotetabs-main" hidden="true">
         <vbox id="PanelUI-remotetabs-buttons">
           <toolbarbutton id="PanelUI-remotetabs-syncnow"
                          align="center"
                          class="subviewbutton"
@@ -536,17 +532,17 @@
                          id="PanelUI-remotetabs-unverified-button"
                          data-l10n-id="appmenu-remote-tabs-opensettings"
                          oncommand="gSync.openPrefs('synced-tabs');"/>
         </vbox>
       </hbox>
     </vbox>
   </panelview>
 
-  <panelview id="PanelUI-fxa" class="PanelUI-subView" descriptionheightworkaround="true">
+  <panelview id="PanelUI-fxa" class="PanelUI-subView">
     <vbox id="PanelUI-fxa-menu" class="panel-subview-body">
       <toolbarbutton id="fxa-manage-account-button"
                      align="center"
                      class="subviewbutton"
                      oncommand="gSync.clickFxAMenuHeaderButton(this);">
         <vbox flex="1">
           <label id="fxa-menu-header-title"
                  crop="end"

--- a/browser/base/content/browser-sitePermissionPanel.js
+++ b/browser/base/content/browser-sitePermissionPanel.js
@@ -533,20 +533,16 @@ var gPermissionPanel = {
         id: "popup",
         state: SitePermissions.getDefault("popup"),
         scope: SitePermissions.SCOPE_PERSISTENT,
       };
       let item = this._createPermissionItem({ permission });
       this._defaultPermissionAnchor.appendChild(item);
       this._createBlockedPopupIndicator(totalBlockedPopups);
     }
-
-    PanelView.forNode(
-      this._permissionPopupMainView
-    ).descriptionHeightWorkaround();
   },
 
   /**
    * Creates a permission item based on the supplied options and returns it.
    * It is up to the caller to actually insert the element somewhere.
    *
    * @param permission - An object containing information representing the
    *                     permission, typically obtained via SitePermissions.jsm
@@ -802,19 +798,16 @@ var gPermissionPanel = {
       }
       SitePermissions.removeFromPrincipal(
         gBrowser.contentPrincipal,
         permission.id,
         browser
       );
 
       this._permissionReloadHint.hidden = false;
-      PanelView.forNode(
-        this._permissionPopupMainView
-      ).descriptionHeightWorkaround();
 
       if (idNoSuffix === "geo") {
         gBrowser.updateBrowserSharing(browser, { geo: false });
       } else if (idNoSuffix === "xr") {
         gBrowser.updateBrowserSharing(browser, { xr: false });
       }
 
       clearCallback();

--- a/browser/base/content/browser-siteProtections.js
+++ b/browser/base/content/browser-siteProtections.js
@@ -1616,17 +1616,17 @@ var gProtectionsHandler = {
       gBrowser.selectedBrowser.getContentBlockingEvents()
     );
   },
 
   /**
    * Update the in-panel UI given a blocking event. Called when the popup
    * is being shown, or when the popup is open while a new event comes in.
    */
-  updatePanelForBlockingEvent(event, isShown) {
+  updatePanelForBlockingEvent(event) {
     // Update the categories:
     for (let blocker of Object.values(this.blockers)) {
       if (blocker.categoryItem.hasAttribute("uidisabled")) {
         continue;
       }
       blocker.categoryItem.classList.toggle(
         "notFound",
         !blocker.isDetected(event)
@@ -1638,26 +1638,16 @@ var gProtectionsHandler = {
     this._protectionsPopup.toggleAttribute("blocking", this.anyBlocking);
     this._protectionsPopup.toggleAttribute("hasException", this.hasException);
 
     this.noTrackersDetectedDescription.hidden = this.anyDetected;
 
     if (this.anyDetected) {
       // Reorder categories if any are in use.
       this.reorderCategoryItems();
-
-      if (isShown) {
-        // Until we encounter a site that triggers them, category elements might
-        // be invisible when descriptionHeightWorkaround gets called, i.e. they
-        // are omitted from the workaround and the content overflows the panel.
-        // Solution: call it manually here.
-        PanelMultiView.forNode(
-          this._protectionsPopupMainView
-        ).descriptionHeightWorkaround();
-      }
     }
   },
 
   reportBlockingEventTelemetry(event, isSimulated, previousState) {
     if (!isSimulated) {
       if (this.hasException && !this.hadShieldState) {
         this.hadShieldState = true;
         this.shieldHistogramAdd(1);
@@ -1751,17 +1741,17 @@ var gProtectionsHandler = {
       this.showNoTrackerTooltipForTPIcon();
     }
 
     // Update the panel if it's open.
     let isPanelOpen = ["showing", "open"].includes(
       this._protectionsPopup?.state
     );
     if (isPanelOpen) {
-      this.updatePanelForBlockingEvent(event, true);
+      this.updatePanelForBlockingEvent(event);
     }
 
     // Notify other consumers, like CFR.
     // Don't send a content blocking event to CFR for
     // tab switches since this will already be done via
     // onStateChange.
     if (!isSimulated) {
       this.notifyContentBlockingEvent(event);

--- a/browser/base/content/browser-sync.js
+++ b/browser/base/content/browser-sync.js
@@ -169,19 +169,16 @@ this.SyncedTabsPanelList = class SyncedT
               paginationInfo.maxTabs
             );
           } else {
             this._appendSyncClient(client, container, labelId);
           }
           fragment.appendChild(container);
         }
         this.tabsList.appendChild(fragment);
-        PanelView.forNode(
-          this.tabsList.closest("panelview")
-        ).descriptionHeightWorkaround();
       })
       .catch(err => {
         Cu.reportError(err);
       })
       .then(() => {
         // an observer for tests.
         Services.obs.notifyObservers(
           null,

--- a/browser/components/controlcenter/content/identityPanel.inc.xhtml
+++ b/browser/components/controlcenter/content/identityPanel.inc.xhtml
@@ -10,19 +10,17 @@
        noautofocus="true"
        aria-labelledby="identity-popup-mainView-panel-header-span"
        onpopupshown="gIdentityHandler.onPopupShown(event);"
        onpopuphidden="gIdentityHandler.onPopupHidden(event);"
        orient="vertical">
 
   <panelmultiview id="identity-popup-multiView"
                   mainViewId="identity-popup-mainView">
-    <panelview id="identity-popup-mainView"
-               role="document"
-               descriptionheightworkaround="true">
+    <panelview id="identity-popup-mainView" role="document">
       <vbox id="identity-popup-mainView-panel-header">
         <label>
           <html:span id="identity-popup-mainView-panel-header-span" role="heading" aria-level="1"/>
         </label>
       </vbox>
       <toolbarseparator></toolbarseparator>
 
       <toolbarbutton id="identity-popup-security-button"
@@ -100,18 +98,17 @@
                 data-l10n-id="identity-clear-site-data"
                 class="subviewbutton panel-subview-footer-button"
                 oncommand="gIdentityHandler.clearSiteData(event);"/>
       </vbox>
     </panelview>
 
     <!-- Security SubView -->
     <panelview id="identity-popup-securityView"
-               role="document"
-               descriptionheightworkaround="true">
+               role="document">
       <vbox class="identity-popup-security-content">
         <vbox class="identity-popup-security-connection">
           <description class="identity-popup-connection-not-secure security-view"
                        when-connection="not-secure secure-cert-user-overridden cert-error-page net-error-page https-only-error-page" data-l10n-id="identity-connection-not-secure-security-view"></description>
           <description class="identity-popup-connection-secure security-view"
                        when-connection="secure secure-ev" data-l10n-id="identity-connection-verified"></description>
         </vbox>
       </vbox>

--- a/browser/components/controlcenter/content/permissionPanel.inc.xhtml
+++ b/browser/components/controlcenter/content/permissionPanel.inc.xhtml
@@ -10,18 +10,17 @@
        noautofocus="true"
        aria-labelledby="permission-popup-mainView-panel-header-span"
        onpopupshown="gPermissionPanel.onPopupShown(event);"
        onpopuphidden="gPermissionPanel.onPopupHidden(event);"
        orient="vertical">
   <panelmultiview id="permission-popup-multiView"
                   mainViewId="permission-popup-mainView">
     <panelview id="permission-popup-mainView"
-               role="document"
-               descriptionheightworkaround="true">
+               role="document">
       <vbox id="permission-popup-mainView-panel-header">
         <label>
           <html:span id="permission-popup-mainView-panel-header-span" role="heading" aria-level="1"/>
         </label>
       </vbox>
       <toolbarseparator></toolbarseparator>
       <hbox class="permission-popup-section">
         <vbox id="permission-popup-permissions-content" flex="1" role="group">

--- a/browser/components/controlcenter/content/protectionsPanel.inc.xhtml
+++ b/browser/components/controlcenter/content/protectionsPanel.inc.xhtml
@@ -11,18 +11,17 @@
        aria-labelledby="protections-popup-main-header-label"
        onpopupshown="gProtectionsHandler.onPopupShown(event);"
        onpopuphidden="gProtectionsHandler.onPopupHidden(event);"
        orient="vertical">
 
   <panelmultiview id="protections-popup-multiView"
                   mainViewId="protections-popup-mainView">
     <panelview id="protections-popup-mainView"
-               role="document"
-               descriptionheightworkaround="true">
+               role="document">
       <vbox id="protections-popup-mainView-panel-header-section">
         <hbox id="protections-popup-mainView-panel-header"
               onclick="gProtectionsHandler.onHeaderClicked(event);">
           <label id="protections-popup-main-header-label" flex="1"
                  role="heading" aria-level="1">
             <html:span id="protections-popup-mainView-panel-header-span"/>
           </label>
           <toolbarbutton id="protections-popup-info-button" class="panel-info-button"
@@ -66,55 +65,45 @@
       <!-- Tracking Protection Section -->
       <toolbarseparator></toolbarseparator>
       <vbox id="tracking-protection-container" class="protections-popup-section">
         <description id="protections-popup-no-trackers-found-description" data-l10n-id="protections-panel-no-trackers-found"></description>
         <tooltip id="protections-popup-not-blocking-why-etp-on-tooltip" data-l10n-id="protections-panel-not-blocking-why-etp-on-tooltip"></tooltip>
         <tooltip id="protections-popup-not-blocking-why-etp-off-tooltip" data-l10n-id="protections-panel-not-blocking-why-etp-off-tooltip"></tooltip>
         <vbox id="protections-popup-content" flex="1">
           <vbox id="protections-popup-category-list">
-            <!-- wrap=true is needed for descriptionheightworkaround, see bug 1564077 -->
             <toolbarbutton id="protections-popup-category-trackers"
                            oncommand="gProtectionsHandler.showTrackersSubview(event); gProtectionsHandler.recordClick('trackers');"
-                           class="protections-popup-category subviewbutton-nav" align="center"
-                           wrap="true">
+                           class="protections-popup-category subviewbutton-nav" align="center">
               <image class="protections-popup-category-icon trackers-icon"/>
               <label flex="1" class="protections-popup-category-label" data-l10n-id="protections-panel-content-blocking-tracking-protection"></label>
             </toolbarbutton>
-            <!-- wrap=true is needed for descriptionheightworkaround, see bug 1564077 -->
             <toolbarbutton id="protections-popup-category-socialblock"
                            oncommand="gProtectionsHandler.showSocialblockerSubview(event); gProtectionsHandler.recordClick('social');"
-                           class="protections-popup-category subviewbutton-nav" align="center"
-                           wrap="true">
+                           class="protections-popup-category subviewbutton-nav" align="center">
               <image class="protections-popup-category-icon socialblock-icon"/>
               <label flex="1"
               class="protections-popup-category-label" data-l10n-id="protections-panel-content-blocking-socialblock"></label>
             </toolbarbutton>
-            <!-- wrap=true is needed for descriptionheightworkaround, see bug 1564077 -->
             <toolbarbutton id="protections-popup-category-cookies"
                            oncommand="gProtectionsHandler.showCookiesSubview(event); gProtectionsHandler.recordClick('cookies');"
-                           class="protections-popup-category subviewbutton-nav" align="center"
-                           wrap="true">
+                           class="protections-popup-category subviewbutton-nav" align="center">
               <image class="protections-popup-category-icon thirdpartycookies-icon"/>
               <label flex="1" id="protections-popup-cookies-category-label"
                      class="protections-popup-category-label"/>
             </toolbarbutton>
-            <!-- wrap=true is needed for descriptionheightworkaround, see bug 1564077 -->
             <toolbarbutton id="protections-popup-category-cryptominers"
                            oncommand="gProtectionsHandler.showCryptominersSubview(event); gProtectionsHandler.recordClick('cryptominers');"
-                           class="protections-popup-category subviewbutton-nav" align="center"
-                           wrap="true">
+                           class="protections-popup-category subviewbutton-nav" align="center">
               <image class="protections-popup-category-icon cryptominers-icon"/>
               <label flex="1" class="protections-popup-category-label" data-l10n-id="protections-panel-content-blocking-cryptominers-label"></label>
             </toolbarbutton>
-            <!-- wrap=true is needed for descriptionheightworkaround, see bug 1564077 -->
             <toolbarbutton id="protections-popup-category-fingerprinters"
                            oncommand="gProtectionsHandler.showFingerprintersSubview(event); gProtectionsHandler.recordClick('fingerprinters');"
-                           class="protections-popup-category subviewbutton-nav" align="center"
-                           wrap="true">
+                           class="protections-popup-category subviewbutton-nav" align="center">
               <image class="protections-popup-category-icon fingerprinters-icon"/>
               <label flex="1" class="protections-popup-category-label" data-l10n-id="protections-panel-content-blocking-fingerprinters-label"></label>
             </toolbarbutton>
             <description id="protections-popup-blocking-section-header"
                          role="heading"
                          aria-level="2" data-l10n-id="protections-panel-blocking-label"></description>
             <hbox id="protections-popup-not-blocking-section-header" flex="1">
               <description id="protections-popup-not-blocking-section-description" flex="1" role="heading" aria-level="2" data-l10n-id="protections-panel-not-blocking-label"></description>
@@ -128,61 +117,54 @@
                          role="heading"
                          aria-level="2" data-l10n-id="protections-panel-not-found-label"></description>
           </vbox>
         </vbox>
       </vbox>
 
       <toolbarseparator></toolbarseparator>
       <vbox id="protections-popup-footer" class="protections-popup-section">
-        <!-- wrap=true is needed for descriptionheightworkaround, see bug 1564077 -->
         <toolbarbutton id="protections-popup-settings-button"
                        class="protections-popup-footer-button"
-                       wrap="true"
                        oncommand="gProtectionsHandler.openPreferences(); gProtectionsHandler.recordClick('settings');">
           <image class="protections-popup-footer-icon protections-popup-settings-icon"/>
           <label class="protections-popup-footer-button-label" flex="1" data-l10n-id="protections-panel-settings-label"></label>
           <label id="protections-popup-footer-protection-type-label"></label>
         </toolbarbutton>
         <stack id="protections-popup-show-report-stack">
-          <!-- wrap=true is needed for descriptionheightworkaround, see bug 1564077 -->
           <toolbarbutton id="protections-popup-show-report-button"
                          class="protections-popup-footer-button"
-                         wrap="true"
                          oncommand="gProtectionsHandler.openProtections(true); gProtectionsHandler.recordClick('full_report');">
             <image class="protections-popup-footer-icon protections-popup-show-report-icon"/>
             <label class="protections-popup-footer-button-label" flex="1" data-l10n-id="protections-panel-protectionsdashboard-label"></label>
           </toolbarbutton>
           <hbox id="protections-popup-trackers-blocked-counter-box"
                 align="center">
             <description id="protections-popup-trackers-blocked-counter-description"
                          onclick="gProtectionsHandler.openProtections(true);"/>
           </hbox>
         </stack>
       </vbox>
 
       <toolbarseparator id="protections-popup-milestones-separator"/>
       <hbox id="protections-popup-milestones" class="protections-popup-section">
-        <!-- wrap=true is needed for descriptionheightworkaround, see bug 1564077 -->
         <toolbarbutton id="protections-popup-milestones-content"
                        flex="1"
-                       wrap="true"
                        oncommand="gProtectionsHandler.openProtections(true); gProtectionsHandler.recordClick('milestone_message');">
           <description id="protections-popup-milestones-text" flex="1"
                        role="heading" aria-level="2"/>
           <image id="protections-popup-milestones-illustration"/>
         </toolbarbutton>
       </hbox>
     </panelview>
 
     <!-- Site Not Working? SubView -->
     <panelview id="protections-popup-siteNotWorkingView"
                role="document"
                data-l10n-id="protections-panel-site-not-working-view"
-               descriptionheightworkaround="true"
                flex="1">
         <hbox id="protections-popup-siteNotWorkingView-header">
           <vbox class="protections-popup-tp-switch-label-box" flex="1">
             <label class="protections-popup-tp-switch-on-header"
                    role="heading"
                    aria-level="1" data-l10n-id="protections-panel-etp-on-header"></label>
             <label class="protections-popup-tp-switch-off-header"
                    role="heading"
@@ -209,18 +191,17 @@
           <label id="protections-popup-siteNotWorkingView-sendReport"
             onclick="gProtectionsHandler.showSendReportView(); gProtectionsHandler.recordClick('send_report_link');"
             class="text-link" data-l10n-id="protections-panel-site-not-working-view-send-report"></label>
         </vbox>
     </panelview>
 
     <!-- Trackers SubView -->
     <panelview id="protections-popup-trackersView"
-               role="document"
-               descriptionheightworkaround="true">
+               role="document">
         <vbox id="protections-popup-trackersView-description" class="protections-popup-description">
           <description data-l10n-id="protections-panel-tracking-content"></description>
           <hbox id="protections-popup-trackersView-shim-allow-hint"
                 class="protections-popup-shim-allow-hint">
             <image class="protections-popup-shim-allow-hint-icon"></image>
             <vbox flex="1">
               <description data-l10n-id="protections-panel-description-shim-allowed">
               </description>
@@ -238,18 +219,17 @@
         <toolbarbutton id="protections-popup-trackersView-settings-button"
                 data-l10n-id="protections-panel-content-blocking-manage-settings"
                 class="subviewbutton panel-subview-footer-button"
                 oncommand="gProtectionsHandler.openPreferences(); gProtectionsHandler.recordClick('subview_settings', 'trackers');"/>
     </panelview>
 
     <!-- Social Block SubView -->
     <panelview id="protections-popup-socialblockView"
-               role="document"
-               descriptionheightworkaround="true">
+               role="document">
         <vbox id="protections-popup-socialblockView-heading" class="protections-popup-description">
           <description data-l10n-id="protections-panel-social-media-trackers"></description>
           <hbox id="protections-popup-socialblockView-shim-allow-hint"
                 class="protections-popup-shim-allow-hint">
             <image class="protections-popup-shim-allow-hint-icon"></image>
             <vbox flex="1">
               <description data-l10n-id="protections-panel-description-shim-allowed">
               </description>
@@ -267,35 +247,33 @@
         <toolbarbutton id="protections-popup-socialblockView-settings-button"
                 data-l10n-id="protections-panel-content-blocking-manage-settings"
                 class="subviewbutton panel-subview-footer-button"
                 oncommand="gProtectionsHandler.openPreferences(); gProtectionsHandler.recordClick('subview_settings', 'social');"/>
     </panelview>
 
     <!-- Cookies SubView -->
     <panelview id="protections-popup-cookiesView"
-               role="document"
-               descriptionheightworkaround="true">
+               role="document">
         <vbox id="protections-popup-cookiesView-heading" class="protections-popup-description">
           <description data-l10n-id="protections-panel-cross-site-tracking-cookies"></description>
         </vbox>
         <toolbarseparator></toolbarseparator>
         <vbox id="protections-popup-cookiesView-list" class="protections-popup-list">
         </vbox>
         <toolbarseparator></toolbarseparator>
         <toolbarbutton id="protections-popup-cookiesView-settings-button"
                   data-l10n-id="protections-panel-content-blocking-manage-settings"
                   class="subviewbutton panel-subview-footer-button"
                   oncommand="gProtectionsHandler.openPreferences(); gProtectionsHandler.recordClick('subview_settings', 'cookies');"/>
     </panelview>
 
     <!-- Fingerprinters SubView -->
     <panelview id="protections-popup-fingerprintersView"
-               role="document"
-               descriptionheightworkaround="true">
+               role="document">
         <vbox id="protections-popup-fingerprinters-heading" class="protections-popup-description">
           <description data-l10n-id="protections-panel-fingerprinters"></description>
           <hbox id="protections-popup-fingerprintersView-shim-allow-hint"
                 class="protections-popup-shim-allow-hint">
             <image class="protections-popup-shim-allow-hint-icon"></image>
             <vbox flex="1">
               <description data-l10n-id="protections-panel-description-shim-allowed">
               </description>
@@ -313,18 +291,17 @@
         <toolbarbutton id="protections-popup-fingerprintersView-settings-button"
                   data-l10n-id="protections-panel-content-blocking-manage-settings"
                   class="subviewbutton panel-subview-footer-button"
                   oncommand="gProtectionsHandler.openPreferences(); gProtectionsHandler.recordClick('subview_settings', 'fingerprinters');"/>
     </panelview>
 
     <!-- Cryptominers SubView -->
     <panelview id="protections-popup-cryptominersView"
-               role="document"
-               descriptionheightworkaround="true">
+               role="document">
         <vbox id="protections-popup-cryptominers-heading" class="protections-popup-description">
           <description data-l10n-id="protections-panel-cryptominers"></description>
           <hbox id="protections-popup-cryptominersView-shim-allow-hint"
                 class="protections-popup-shim-allow-hint">
             <image class="protections-popup-shim-allow-hint-icon"></image>
             <vbox flex="1">
               <description data-l10n-id="protections-panel-description-shim-allowed">
               </description>
@@ -342,18 +319,17 @@
         <toolbarbutton id="protections-popup-cryptominersView-settings-button"
                   data-l10n-id="protections-panel-content-blocking-manage-settings"
                   class="subviewbutton panel-subview-footer-button"
                   oncommand="gProtectionsHandler.openPreferences(); gProtectionsHandler.recordClick('subview_settings', 'cryptominers');"/>
     </panelview>
 
     <!-- Send Report SubView -->
     <panelview id="protections-popup-sendReportView"
-               data-l10n-id="protections-panel-content-blocking-breakage-report-view"
-               descriptionheightworkaround="true">
+               data-l10n-id="protections-panel-content-blocking-breakage-report-view">
         <vbox id="protections-popup-sendReportView-heading">
           <description data-l10n-id="protections-panel-content-blocking-breakage-report-view-description">
             <label id="protections-popup-sendReportView-learn-more"
                    is="text-link" data-l10n-name="learn-more"></label>
           </description>
         </vbox>
         <vbox id="protections-popup-sendReportView-body" class="panel-view-body-unscrollable">
           <vbox class="protections-popup-sendReportView-collection-section">

--- a/browser/components/customizableui/PanelMultiView.jsm
+++ b/browser/components/customizableui/PanelMultiView.jsm
@@ -126,17 +126,16 @@ const BLOCKERS_TIMEOUT_MS = 10000;
 const TRANSITION_PHASES = Object.freeze({
   START: 1,
   PREPARE: 2,
   TRANSITION: 3,
 });
 
 let gNodeToObjectMap = new WeakMap();
 let gWindowsWithUnloadHandler = new WeakSet();
-let gMultiLineElementsMap = new WeakMap();
 
 /**
  * Allows associating an object to a node lazily using a weak map.
  *
  * Classes deriving from this one may be easily converted to Custom Elements,
  * although they would lose the ability of being associated lazily.
  */
 var AssociatedToNode = class {
@@ -822,17 +821,16 @@ var PanelMultiView = class extends Assoc
     // reset all the properties that may be set on a subview.
     nextPanelView.mainview = true;
     nextPanelView.headerText = "";
     nextPanelView.minMaxWidth = 0;
     nextPanelView.minMaxHeight = 0;
 
     // Ensure the view will be visible once the panel is opened.
     nextPanelView.visible = true;
-    nextPanelView.descriptionHeightWorkaround();
 
     return true;
   }
 
   /**
    * Opens the specified PanelView and dispatches the ViewShowing event, which
    * can be used to populate the subview or cancel the operation.
    *
@@ -986,30 +984,25 @@ var PanelMultiView = class extends Assoc
       // Until the header is visible, it has 0 height.
       // Wait for layout before measuring it
       let header = viewNode.firstElementChild;
       if (header && header.classList.contains("panel-header")) {
         viewRect.height += await window.promiseDocumentFlushed(() => {
           return this._getBoundsWithoutFlushing(header).height;
         });
       }
-      await nextPanelView.descriptionHeightWorkaround();
       // Bail out if the panel was closed in the meantime.
       if (!nextPanelView.isOpenIn(this)) {
         return;
       }
     } else {
       this._offscreenViewStack.style.minHeight = olderView.knownHeight + "px";
       this._offscreenViewStack.appendChild(viewNode);
       nextPanelView.visible = true;
 
-      // Now that the subview is visible, we can check the height of the
-      // description elements it contains.
-      await nextPanelView.descriptionHeightWorkaround();
-
       viewRect = await window.promiseDocumentFlushed(() => {
         return this._getBoundsWithoutFlushing(viewNode);
       });
       // Bail out if the panel was closed in the meantime.
       if (!nextPanelView.isOpenIn(this)) {
         return;
       }
 
@@ -1262,17 +1255,16 @@ var PanelMultiView = class extends Assoc
       }
       case "popupshown":
         // The main view is always open and visible when the panel is first
         // shown, so we can check the height of the description elements it
         // contains and notify consumers using the ViewShown event. In order to
         // minimize flicker we need to allow synchronous reflows, and we still
         // make sure the ViewShown event is dispatched synchronously.
         let mainPanelView = this.openViews[0];
-        mainPanelView.descriptionHeightWorkaround(true).catch(Cu.reportError);
         this._activateView(mainPanelView);
         break;
       case "popuphidden": {
         // WebExtensions consumers can hide the popup from viewshowing, or
         // mid-transition, which disrupts our state:
         this._transitioning = false;
         this._viewContainer.removeAttribute("panelopen");
         this._cleanupTransitionPhase();
@@ -1463,134 +1455,16 @@ var PanelView = class extends Associated
    */
   captureKnownSize() {
     let rect = this._getBoundsWithoutFlushing(this.node);
     this.knownWidth = rect.width;
     this.knownHeight = rect.height;
   }
 
   /**
-   * If the main view or a subview contains wrapping elements, the attribute
-   * "descriptionheightworkaround" should be set on the view to force all the
-   * wrapping "description", "label" or "toolbarbutton" elements to a fixed
-   * height. If the attribute is set and the visibility, contents, or width
-   * of any of these elements changes, this function should be called to
-   * refresh the calculated heights.
-   *
-   * @param allowSyncReflows
-   *        If set to true, the function takes a path that allows synchronous
-   *        reflows, but minimizes flickering. This is used for the main view
-   *        because we cannot use the workaround off-screen.
-   */
-  async descriptionHeightWorkaround(allowSyncReflows = false) {
-    if (!this.node.hasAttribute("descriptionheightworkaround")) {
-      // This view does not require the workaround.
-      return;
-    }
-
-    const profilerMarkerStartTime = Cu.now();
-
-    // We batch DOM changes together in order to reduce synchronous layouts.
-    // First we reset any change we may have made previously. The first time
-    // this is called, and in the best case scenario, this has no effect.
-    let items = [];
-    let collectItems = () => {
-      // Non-hidden <label> or <description> elements that also aren't empty
-      // and also don't have a value attribute can be multiline (if their
-      // text content is long enough).
-      let isMultiline = ":not([hidden],[value],:empty)";
-      let selector = [
-        "description" + isMultiline,
-        "label" + isMultiline,
-        "toolbarbutton[wrap]:not([hidden])",
-      ].join(",");
-      for (let element of this.node.querySelectorAll(selector)) {
-        // Ignore items in hidden containers.
-        if (element.closest("[hidden]")) {
-          continue;
-        }
-
-        // Ignore content inside a <toolbarbutton>
-        if (
-          element.tagName != "toolbarbutton" &&
-          element.closest("toolbarbutton")
-        ) {
-          continue;
-        }
-
-        // Take the label for toolbarbuttons; it only exists on those elements.
-        element = element.multilineLabel || element;
-
-        let bounds = element.getBoundingClientRect();
-        let previous = gMultiLineElementsMap.get(element);
-        // We don't need to (re-)apply the workaround for invisible elements or
-        // on elements we've seen before and haven't changed in the meantime.
-        if (
-          !bounds.width ||
-          !bounds.height ||
-          (previous &&
-            element.textContent == previous.textContent &&
-            bounds.width == previous.bounds.width)
-        ) {
-          continue;
-        }
-
-        items.push({ element });
-      }
-    };
-    if (allowSyncReflows) {
-      collectItems();
-    } else {
-      await this.window.promiseDocumentFlushed(collectItems);
-      // Bail out if the panel was closed in the meantime.
-      if (!this.node.panelMultiView) {
-        return;
-      }
-    }
-
-    // Removing the 'height' property will only cause a layout flush in the next
-    // loop below if it was set.
-    for (let item of items) {
-      item.element.style.removeProperty("height");
-    }
-
-    // We now read the computed style to store the height of any element that
-    // may contain wrapping text.
-    let measureItems = () => {
-      for (let item of items) {
-        item.bounds = item.element.getBoundingClientRect();
-      }
-    };
-    if (allowSyncReflows) {
-      measureItems();
-    } else {
-      await this.window.promiseDocumentFlushed(measureItems);
-      // Bail out if the panel was closed in the meantime.
-      if (!this.node.panelMultiView) {
-        return;
-      }
-    }
-
-    // Now we can make all the necessary DOM changes at once.
-    for (let { element, bounds } of items) {
-      gMultiLineElementsMap.set(element, {
-        bounds,
-        textContent: element.textContent,
-      });
-      element.style.height = bounds.height + "px";
-    }
-
-    ChromeUtils.addProfilerMarker(
-      "PMV.descriptionHeightWorkaround()",
-      profilerMarkerStartTime,
-      `<${this.node.tagName} id="${this.node.id}">`
-    );
-  }
-
-  /**
    * Determine whether an element can only be navigated to with tab/shift+tab,
    * not the arrow keys.
    */
   _isNavigableWithTabOnly(element) {
     let tag = element.localName;
     return (
       tag == "menulist" ||
       tag == "radiogroup" ||

--- a/browser/components/downloads/content/downloadsPanel.inc.xhtml
+++ b/browser/components/downloads/content/downloadsPanel.inc.xhtml
@@ -165,17 +165,16 @@
                     pack="start"/>
           </vbox>
         </stack>
       </vbox>
     </panelview>
 
     <panelview id="downloadsPanel-blockedSubview"
                data-l10n-id="downloads-details"
-               descriptionheightworkaround="true"
                class="PanelUI-subView">
       <vbox class="panel-view-body-unscrollable">
         <hbox class="downloadsPanel-blockedSubview-title-box">
           <description id="downloadsPanel-blockedSubview-title"/>
           <image class="downloadsPanel-blockedSubview-image"/>
         </hbox>
         <description id="downloadsPanel-blockedSubview-details1"/>
         <description id="downloadsPanel-blockedSubview-details2"/>

--- a/devtools/client/performance-new/popup/panel.jsm.js
+++ b/devtools/client/performance-new/popup/panel.jsm.js
@@ -130,19 +130,16 @@ function createViewControllers(state, el
         );
         elements.presetsMenuList.value = presetName;
       } else {
         elements.presetDescription.style.display = "none";
         // We don't remove the l10n-id attribute as the element is hidden anyway.
         // It will be updated again when it's displayed next time.
         elements.presetsMenuList.value = "custom";
       }
-      const { PanelMultiView } = lazy.PanelMultiView();
-      // Update the description height sizing.
-      PanelMultiView.forNode(elements.panelview).descriptionHeightWorkaround();
     },
 
     updateProfilerState() {
       if (Services.profiler.IsActive()) {
         elements.inactive.hidden = true;
         elements.active.hidden = false;
         elements.settingsSection.hidden = true;
         elements.contentRecording.hidden = false;
@@ -216,21 +213,16 @@ function initializeView(state, elements,
   elements.window.requestAnimationFrame(() => {
     // Allow the elements to layout once, the updateInfoCollapse implementation measures
     // the size of the container. It needs to wait a second before the bounding box
     // returns an actual size.
     view.updateInfoCollapse();
     view.updateProfilerState();
     view.updatePresets();
 
-    // XUL <description> elements don't vertically size correctly, this is
-    // the workaround for it.
-    const { PanelMultiView } = lazy.PanelMultiView();
-    PanelMultiView.forNode(elements.panelview).descriptionHeightWorkaround();
-
     // Now wait for another rAF, and turn the animations back on.
     elements.window.requestAnimationFrame(() => {
       elements.header.setAttribute("animationready", "true");
     });
   });
 }
 
 /**