diff --git a/caps/tests/unit/test_origin.js b/caps/tests/unit/test_origin.js
index 9e00c750dde9..e575976203b7 100644
--- a/caps/tests/unit/test_origin.js
+++ b/caps/tests/unit/test_origin.js
@@ -203,7 +203,7 @@ function run_test() {
 
   // check that we can create an empty origin attributes dict with default
   // members and values.
-  emptyAttrs = ChromeUtils.fillNonDefaultOriginAttributes({});
+  emptyAttrs = ChromeUtils.createDefaultOriginAttributes();
   checkValues(emptyAttrs);
 
   var uri = "http://example.org";
@@ -226,7 +226,7 @@ function run_test() {
 
   // check that we can create an origin attributes from a dict properly
   tests.forEach(function(t) {
-    let attrs = ChromeUtils.fillNonDefaultOriginAttributes(t[1]);
+    let attrs = ChromeUtils.createOriginAttributesFromDict(t[1]);
     checkValues(attrs, t[1]);
     do_check_eq(ChromeUtils.originAttributesToSuffix(attrs), t[0]);
   });
diff --git a/dom/base/ChromeUtils.cpp b/dom/base/ChromeUtils.cpp
index 0923226d5628..f8acc6db2282 100644
--- a/dom/base/ChromeUtils.cpp
+++ b/dom/base/ChromeUtils.cpp
@@ -70,6 +70,13 @@ ChromeUtils::OriginAttributesMatchPattern(dom::GlobalObject& aGlobal,
   return pattern.Matches(attrs);
 }
 
+/* static */ void
+ChromeUtils::CreateDefaultOriginAttributes(dom::GlobalObject& aGlobal,
+                                      dom::OriginAttributesDictionary& aAttrs)
+{
+  aAttrs = GenericOriginAttributes();
+}
+
 /* static */ void
 ChromeUtils::CreateOriginAttributesFromOrigin(dom::GlobalObject& aGlobal,
                                        const nsAString& aOrigin,
@@ -86,7 +93,7 @@ ChromeUtils::CreateOriginAttributesFromOrigin(dom::GlobalObject& aGlobal,
 }
 
 /* static */ void
-ChromeUtils::FillNonDefaultOriginAttributes(dom::GlobalObject& aGlobal,
+ChromeUtils::CreateOriginAttributesFromDict(dom::GlobalObject& aGlobal,
                                  const dom::OriginAttributesDictionary& aAttrs,
                                  dom::OriginAttributesDictionary& aNewAttrs)
 {
diff --git a/dom/base/ChromeUtils.h b/dom/base/ChromeUtils.h
index 35a6d6cc5a68..3378dac3af4e 100644
--- a/dom/base/ChromeUtils.h
+++ b/dom/base/ChromeUtils.h
@@ -58,6 +58,10 @@ public:
                                const dom::OriginAttributesDictionary& aAttrs,
                                const dom::OriginAttributesPatternDictionary& aPattern);
 
+  static void
+  CreateDefaultOriginAttributes(dom::GlobalObject& aGlobal,
+                                dom::OriginAttributesDictionary& aAttrs);
+
   static void
   CreateOriginAttributesFromOrigin(dom::GlobalObject& aGlobal,
                                    const nsAString& aOrigin,
@@ -65,7 +69,7 @@ public:
                                    ErrorResult& aRv);
 
   static void
-  FillNonDefaultOriginAttributes(dom::GlobalObject& aGlobal,
+  CreateOriginAttributesFromDict(dom::GlobalObject& aGlobal,
                                  const dom::OriginAttributesDictionary& aAttrs,
                                  dom::OriginAttributesDictionary& aNewAttrs);
 
diff --git a/dom/webidl/ChromeUtils.webidl b/dom/webidl/ChromeUtils.webidl
index f0e5b03ba465..e22201341b2a 100644
--- a/dom/webidl/ChromeUtils.webidl
+++ b/dom/webidl/ChromeUtils.webidl
@@ -29,6 +29,16 @@ interface ChromeUtils : ThreadSafeChromeUtils {
   originAttributesMatchPattern(optional OriginAttributesDictionary originAttrs,
                                optional OriginAttributesPatternDictionary pattern);
 
+  /**
+   * Returns an OriginAttributesDictionary with all default attributes added
+   * and assigned default values.
+   *
+   * @returns                 An OriginAttributesDictionary populated with the
+   *                          default attributes added and assigned default values.
+   */
+  static OriginAttributesDictionary
+  createDefaultOriginAttributes();
+
   /**
    * Returns an OriginAttributesDictionary with values from the |origin| suffix
    * and unspecified attributes added and assigned default values.
@@ -52,7 +62,7 @@ interface ChromeUtils : ThreadSafeChromeUtils {
    *                          default values.
    */
   static OriginAttributesDictionary
-  fillNonDefaultOriginAttributes(optional OriginAttributesDictionary originAttrs);
+  createOriginAttributesFromDict(optional OriginAttributesDictionary originAttrs);
 
   /**
    * Returns true if the 2 OriginAttributes are equal.
diff --git a/toolkit/components/extensions/ExtensionContent.jsm b/toolkit/components/extensions/ExtensionContent.jsm
index 19906367f4d4..c5a11df3439d 100644
--- a/toolkit/components/extensions/ExtensionContent.jsm
+++ b/toolkit/components/extensions/ExtensionContent.jsm
@@ -296,18 +296,13 @@ class ExtensionContext extends BaseContext {
     let contentPrincipal = contentWindow.document.nodePrincipal;
     let ssm = Services.scriptSecurityManager;
 
-    // copy origin attributes from the content window origin attributes to
-    // preserve the user context id. overwrite the addonId.
-    let attrs = ChromeUtils.fillNonDefaultOriginAttributes(contentPrincipal.originAttributes);
-    attrs.addonId = extensionId;
-    let extensionPrincipal = ssm.createCodebasePrincipal(this.extension.baseURI, attrs);
+    let extensionPrincipal = ssm.createCodebasePrincipal(this.extension.baseURI, {addonId: extensionId});
     Object.defineProperty(this, "principal",
                           {value: extensionPrincipal, enumerable: true, configurable: true});
 
     if (ssm.isSystemPrincipal(contentPrincipal)) {
       // Make sure we don't hand out the system principal by accident.
-      // also make sure that the null principal has the right origin attributes
-      prin = ssm.createNullPrincipal(attrs);
+      prin = Cc["@mozilla.org/nullprincipal;1"].createInstance(Ci.nsIPrincipal);
     } else {
       prin = [contentPrincipal, extensionPrincipal];
     }