diff --git a/browser/base/content/browser.js b/browser/base/content/browser.js
index 94ae7ef4fd5..b32f70cfc16 100644
--- a/browser/base/content/browser.js
+++ b/browser/base/content/browser.js
@@ -7523,14 +7523,14 @@ var StyleEditor = {
       this.StyleEditorManager.selectEditor(win);
       return win;
     } else {
-      return this.StyleEditorManager.newEditor(contentWindow,
+      return this.StyleEditorManager.newEditor(contentWindow, window,
                                                aSelectedStyleSheet, aLine, aCol);
     }
   },
 
   toggle: function SE_toggle()
   {
-    this.StyleEditorManager.toggleEditor(gBrowser.contentWindow);
+    this.StyleEditorManager.toggleEditor(gBrowser.contentWindow, window);
   }
 };
 
diff --git a/browser/devtools/styleeditor/StyleEditor.jsm b/browser/devtools/styleeditor/StyleEditor.jsm
index 9a483ce80dc..a43a285d3bb 100644
--- a/browser/devtools/styleeditor/StyleEditor.jsm
+++ b/browser/devtools/styleeditor/StyleEditor.jsm
@@ -1315,11 +1315,12 @@ StyleEditorManager.prototype = {
    * Open a new editor.
    *
    * @param {Window} content window.
+   * @param {Window} chrome window.
    * @param {CSSStyleSheet} [aSelectedStyleSheet] default Stylesheet.
    * @param {Number} [aLine] Line to which the caret should be moved (one-indexed).
    * @param {Number} [aCol] Column to which the caret should be moved (one-indexed).
    */
-  newEditor: function SEM_newEditor(aContentWindow, aSelectedStyleSheet, aLine, aCol) {
+  newEditor: function SEM_newEditor(aContentWindow, aChromeWindow, aSelectedStyleSheet, aLine, aCol) {
     const CHROME_URL = "chrome://browser/content/styleeditor.xul";
     const CHROME_WINDOW_FLAGS = "chrome,centerscreen,resizable,dialog=no";
 
@@ -1330,7 +1331,7 @@ StyleEditorManager.prototype = {
       col: aCol
     };
     args.wrappedJSObject = args;
-    let chromeWindow = Services.ww.openWindow(null, CHROME_URL, "_blank",
+    let chromeWindow = Services.ww.openWindow(aChromeWindow, CHROME_URL, "_blank",
                                               CHROME_WINDOW_FLAGS, args);
 
     chromeWindow.onunload = function() {
@@ -1353,12 +1354,12 @@ StyleEditorManager.prototype = {
    *
    * @param {Window} associated content window.
    */
-  toggleEditor: function SEM_toggleEditor(aContentWindow) {
+  toggleEditor: function SEM_toggleEditor(aContentWindow, aChromeWindow) {
     let editor = this.getEditorForWindow(aContentWindow);
     if (editor) {
       editor.close();
     } else {
-      this.newEditor(aContentWindow);
+      this.newEditor(aContentWindow, aChromeWindow);
     }
   },
 
diff --git a/browser/devtools/styleeditor/test/browser_styleeditor_private.js b/browser/devtools/styleeditor/test/browser_styleeditor_private.js
index d0f84252f35..593593b0832 100644
--- a/browser/devtools/styleeditor/test/browser_styleeditor_private.js
+++ b/browser/devtools/styleeditor/test/browser_styleeditor_private.js
@@ -6,6 +6,8 @@
 // content CSS files in the permanent cache when opened from PB mode.
 
 function checkDiskCacheFor(host) {
+  let foundPrivateData = false;
+
   let visitor = {
     visitDevice: function(deviceID, deviceInfo) {
       if (deviceID == "disk")
@@ -15,10 +17,12 @@ function checkDiskCacheFor(host) {
     
     visitEntry: function(deviceID, entryInfo) {
       info(entryInfo.key);
-      is(entryInfo.key.contains(host), false, "web content present in disk cache");
+      foundPrivateData |= entryInfo.key.contains(host);
+      is(foundPrivateData, false, "web content present in disk cache");
     }
   };
   cache.visitEntries(visitor);
+  is(foundPrivateData, false, "private data present in disk cache");
 }
 
 const TEST_HOST = 'mochi.test:8888';