Backed out changeset c0772946156f (bug 1369729) for failing browser-chrome's browser_appmenu_reflows.js with unexpected uninterruptible reflow. r=backout

browser/components/controlcenter/content/panel.inc.xul

@@ -16,9 +16,10 @@
   </broadcasterset>
 
   <panelmultiview id="identity-popup-multiView"
-                  mainViewId="identity-popup-mainView">
-    <panelview id="identity-popup-mainView" flex="1"
-               descriptionheightworkaround="true">
+                  mainViewId="identity-popup-mainView"
+                  descriptionheightworkaround="true">
+    <panelview id="identity-popup-mainView" flex="1">
+
       <!-- Security Section -->
       <hbox id="identity-popup-security" class="identity-popup-section">
         <vbox id="identity-popup-security-content" flex="1">
@@ -96,8 +97,7 @@
     </panelview>
 
     <!-- Security SubView -->
-    <panelview id="identity-popup-securityView"
-               descriptionheightworkaround="true">
+    <panelview id="identity-popup-securityView">
       <vbox id="identity-popup-securityView-header">
         <label class="plain">
           <label class="identity-popup-headline identity-popup-host"></label>

browser/components/customizableui/CustomizableWidgets.jsm

@@ -442,8 +442,6 @@ const CustomizableWidgets = [
           }
         }
         this._tabsList.appendChild(fragment);
-        let panelView = this._tabsList.closest("panelview");
-        panelView.panelMultiView.descriptionHeightWorkaround(panelView);
       }).catch(err => {
         Cu.reportError(err);
       }).then(() => {

browser/components/customizableui/PanelMultiView.jsm

@@ -1012,10 +1012,10 @@ this.PanelMultiView = class {
   /**
    * 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.
+   * "description" or wrapping 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.
    *
    * This may trigger a synchronous layout.
    *
@@ -1024,7 +1024,7 @@ this.PanelMultiView = class {
    *        view if omitted.
    */
   descriptionHeightWorkaround(viewNode = this._mainView) {
-    if (!viewNode.hasAttribute("descriptionheightworkaround")) {
+    if (!this.node.hasAttribute("descriptionheightworkaround")) {
       // This view does not require the workaround.
       return;
     }
@@ -1033,20 +1033,8 @@ this.PanelMultiView = class {
     // 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 = [];
-    // 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(:-moz-any([hidden],[value],:empty))";
-    let selector = [
-      "description" + isMultiline,
-      "label" + isMultiline,
-      "toolbarbutton[wrap]:not([hidden])",
-    ].join(",");
-    for (let element of viewNode.querySelectorAll(selector)) {
-      // Ignore items in hidden containers.
-      if (element.closest("[hidden]")) {
-        continue;
-      }
+    for (let element of viewNode.querySelectorAll(
+         "description:not([hidden]):not([value]),toolbarbutton[wrap]:not([hidden])")) {
       // Take the label for toolbarbuttons; it only exists on those elements.
       element = element.labelElement || element;
 

browser/components/customizableui/content/panelUI.inc.xul

@@ -11,8 +11,7 @@
        noautofocus="true">
   <panelmultiview id="PanelUI-multiView" mainViewId="PanelUI-mainView"
                   viewCacheId="appMenu-viewCache">
-    <panelview id="PanelUI-mainView" context="customizationPanelContextMenu"
-               descriptionheightworkaround="true">
+    <panelview id="PanelUI-mainView" context="customizationPanelContextMenu">
       <vbox id="PanelUI-contents-scroller">
         <vbox id="PanelUI-contents" class="panelUI-grid"/>
       </vbox>
@@ -110,8 +109,7 @@
                      oncommand="PlacesCommandHook.showPlacesOrganizer('History'); CustomizableUI.hidePanelForNode(this);"/>
     </panelview>
 
-    <panelview id="PanelUI-remotetabs" flex="1" class="PanelUI-subView"
-               descriptionheightworkaround="true">
+    <panelview id="PanelUI-remotetabs" flex="1" class="PanelUI-subView">
       <label value="&appMenuRemoteTabs.label;" class="panel-subview-header"/>
       <vbox class="panel-subview-body">
         <!-- this widget has 3 boxes in the body, but only 1 is ever visible -->
@@ -300,8 +298,7 @@
       </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=""/>
@@ -515,9 +512,9 @@
        position="bottomcenter topright"
        noautofocus="true">
   <photonpanelmultiview id="appMenu-multiView" mainViewId="appMenu-mainView"
+                        descriptionheightworkaround="true"
                         viewCacheId="appMenu-viewCache">
-    <panelview id="appMenu-mainView" class="PanelUI-subView"
-               descriptionheightworkaround="true">
+    <panelview id="appMenu-mainView" class="PanelUI-subView">
       <vbox class="panel-subview-body">
         <vbox id="appMenu-addon-banners"/>
         <toolbarbutton class="panel-banner-item"

browser/components/downloads/content/downloadsOverlay.xul

@@ -107,7 +107,8 @@
       </menupopup>
 
       <panelmultiview id="downloadsPanel-multiView"
-                      mainViewId="downloadsPanel-mainView">
+                      mainViewId="downloadsPanel-mainView"
+                      descriptionheightworkaround="true">
 
         <panelview id="downloadsPanel-mainView">
           <vbox class="panel-view-body-unscrollable">
@@ -156,8 +157,7 @@
           </vbox>
         </panelview>
 
-        <panelview id="downloadsPanel-blockedSubview"
-                   descriptionheightworkaround="true">
+        <panelview id="downloadsPanel-blockedSubview">
           <vbox class="panel-view-body-unscrollable">
             <description id="downloadsPanel-blockedSubview-title"/>
             <description id="downloadsPanel-blockedSubview-details1"/>