--- a/mobile/android/components/SessionStore.js
+++ b/mobile/android/components/SessionStore.js
@@ -6,23 +6,24 @@
 ChromeUtils.import("resource://gre/modules/AppConstants.jsm");
 ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
 ChromeUtils.import("resource://gre/modules/Services.jsm");
 
 XPCOMUtils.defineLazyModuleGetters(this, {
   EventDispatcher: "resource://gre/modules/Messaging.jsm",
   FormData: "resource://gre/modules/FormData.jsm",
   OS: "resource://gre/modules/osfile.jsm",
-  PrivacyLevel: "resource://gre/modules/sessionstore/PrivacyLevel.jsm",
+  PrivacyFilter: "resource://gre/modules/sessionstore/PrivacyFilter.jsm",
   PrivateBrowsingUtils: "resource://gre/modules/PrivateBrowsingUtils.jsm",
   ScrollPosition: "resource://gre/modules/ScrollPosition.jsm",
   SessionHistory: "resource://gre/modules/sessionstore/SessionHistory.jsm",
   SharedPreferences: "resource://gre/modules/SharedPreferences.jsm",
   Task: "resource://gre/modules/Task.jsm",
   TelemetryStopwatch: "resource://gre/modules/TelemetryStopwatch.jsm",
+  Utils: "resource://gre/modules/sessionstore/Utils.jsm",
 });
 
 XPCOMUtils.defineLazyModuleGetter(this, "Log", "resource://gre/modules/AndroidLog.jsm", "AndroidLog");
 
 function dump(a) {
   Services.console.logStringMessage(a);
 }
 
@@ -885,51 +886,23 @@ SessionStore.prototype = {
 
     // Don't bother trying to save text data if we don't have history yet
     let data = aBrowser.__SS_data;
     if (!data || data.entries.length == 0) {
       sendEvent(aBrowser, "SSTabInputCaptured");
       return;
     }
 
-    // Start with storing the main content
+    // Store the form data.
     let content = aBrowser.contentWindow;
-
-    // If the main content document has an associated URL that we are not
-    // allowed to store data for, bail out. We explicitly discard data for any
-    // children as well even if storing data for those frames would be allowed.
-    if (!PrivacyLevel.check(content.document.documentURI)) {
-      sendEvent(aBrowser, "SSTabInputCaptured");
-      return;
-    }
-
-    // Store the main content
-    let formdata = FormData.collect(content) || {};
-
-    // Loop over direct child frames, and store the text data
-    let children = [];
-    for (let i = 0; i < content.frames.length; i++) {
-      let frame = content.frames[i];
-      if (!PrivacyLevel.check(frame.document.documentURI)) {
-        continue;
-      }
-
-      let result = FormData.collect(frame);
-      if (result && Object.keys(result).length) {
-        children[i] = result;
-      }
-    }
-
-    // If any frame had text data, add it to the main form data
-    if (children.length) {
-      formdata.children = children;
-    }
+    let [formdata] = Utils.mapFrameTree(content, FormData.collect);
+    formdata = PrivacyFilter.filterFormData(formdata || {});
 
     // If we found any form data, main content or frames, let's save it
-    if (Object.keys(formdata).length) {
+    if (formdata && Object.keys(formdata).length) {
       data.formdata = formdata;
       log("onTabInput() ran for tab " + aWindow.BrowserApp.getTabForBrowser(aBrowser).id);
       this.saveStateDelayed();
     }
     sendEvent(aBrowser, "SSTabInputCaptured");
   },
 
   onTabScroll: function ss_onTabScroll(aWindow, aBrowser) {
@@ -952,37 +925,20 @@ SessionStore.prototype = {
       return;
     }
 
     // Neither bother if we're yet to restore the previous scroll position.
     if (aBrowser.__SS_restoreDataOnLoad || aBrowser.__SS_restoreDataOnPageshow) {
       return;
     }
 
-    // Start with storing the main content.
+    // Save the scroll position itself.
     let content = aBrowser.contentWindow;
-
-    // Store the main content.
-    let scrolldata = ScrollPosition.collect(content) || {};
-
-    // Loop over direct child frames, and store the scroll positions.
-    let children = [];
-    for (let i = 0; i < content.frames.length; i++) {
-      let frame = content.frames[i];
-
-      let result = ScrollPosition.collect(frame);
-      if (result && Object.keys(result).length) {
-        children[i] = result;
-      }
-    }
-
-    // If any frame had scroll positions, add them to the main scroll data.
-    if (children.length) {
-      scrolldata.children = children;
-    }
+    let [scrolldata] = Utils.mapFrameTree(content, ScrollPosition.collect);
+    scrolldata = scrolldata || {};
 
     // Save the current document resolution.
     let zoom = { value: 1 };
     content.QueryInterface(Ci.nsIInterfaceRequestor).getInterface(
       Ci.nsIDOMWindowUtils).getResolution(zoom);
     scrolldata.zoom = {};
     scrolldata.zoom.resolution = zoom.value;
     log("onTabScroll() zoom level: " + zoom.value);

--- a/mobile/android/tests/browser/chrome/session_formdata_sample.html
+++ b/mobile/android/tests/browser/chrome/session_formdata_sample.html
@@ -1,20 +1,20 @@
 <!DOCTYPE html>
 <html lang="en">
   <head>
     <meta charset="utf-8">
     <title>session_formdata_sample.html</title>
   </head>
   <body>
     <input id="txt" />
+    <iframe id="iframe"></iframe>
 
     <script type="text/javascript">
       let isOuter = window == window.top;
 
       if (isOuter) {
-        let iframe = document.createElement("iframe");
+        let iframe = document.getElementById("iframe");
         iframe.setAttribute("src", "https://example.com" + location.pathname);
-        document.body.appendChild(iframe);
       }
     </script>
   </body>
 </html>