Bug 952401 - Collect scroll and pageStyle data as soon as the frame tree is available r=smacleod

From 84ca4ca357b94a5dc9449627e88bb4e3cde69557 Mon Sep 17 00:00:00 2001

browser/components/sessionstore/content/content-sessionStore.js

@@ -229,6 +229,10 @@ let ScrollPositionListener = {
     }
   },
 
+  onFrameTreeCollected: function () {
+    MessageQueue.push("scroll", () => this.collect());
+  },
+
   onFrameTreeReset: function () {
     MessageQueue.push("scroll", () => null);
   },
@@ -268,6 +272,10 @@ let PageStyleListener = {
     return PageStyle.collect(docShell, gFrameTree);
   },
 
+  onFrameTreeCollected: function () {
+    MessageQueue.push("pageStyle", () => this.collect());
+  },
+
   onFrameTreeReset: function () {
     MessageQueue.push("pageStyle", () => null);
   },

browser/components/sessionstore/src/SessionStore.jsm

@@ -2983,10 +2983,10 @@ let SessionStoreInternal = {
     if (typeof(pageStyle) === "string") {
       PageStyle.restore(aBrowser.docShell, frameList, pageStyle);
     } else {
-      ScrollPosition.restoreTree(aBrowser.contentWindow, scrollPositions);
+      PageStyle.restoreTree(aBrowser.docShell, pageStyle);
     }
 
-    PageStyle.restoreTree(aBrowser.docShell, pageStyle);
+    ScrollPosition.restoreTree(aBrowser.contentWindow, scrollPositions);
     TextAndScrollData.restore(frameList);
 
     let tab = aBrowser.__SS_restore_tab;