--- a/toolkit/content/widgets/browser.xml
+++ b/toolkit/content/widgets/browser.xml
@@ -498,16 +498,22 @@
       </property>
 
       <property name="isSyntheticDocument">
         <getter><![CDATA[
           return this.contentDocument.mozSyntheticDocument;
         ]]></getter>
       </property>
 
+      <property name="hasContentOpener">
+        <getter><![CDATA[
+          return !!this.contentWindow.opener;
+        ]]></getter>
+      </property>
+
       <field name="mPrefs" readonly="true">
         Components.classes['@mozilla.org/preferences-service;1']
                   .getService(Components.interfaces.nsIPrefBranch);
       </field>
 
       <field name="mAtomService" readonly="true">
         Components.classes['@mozilla.org/atom-service;1']
                   .getService(Components.interfaces.nsIAtomService);

--- a/toolkit/content/widgets/remote-browser.xml
+++ b/toolkit/content/widgets/remote-browser.xml
@@ -193,16 +193,23 @@
 
       <field name="_isSyntheticDocument">false</field>
       <property name="isSyntheticDocument">
         <getter><![CDATA[
           return this._isSyntheticDocument;
         ]]></getter>
       </property>
 
+      <property name="hasContentOpener">
+        <getter><![CDATA[
+          let {frameLoader} = this.QueryInterface(Ci.nsIFrameLoaderOwner);
+          return frameLoader.tabParent.hasContentOpener;
+        ]]></getter>
+      </property>
+
       <field name="_outerWindowID">null</field>
       <property name="outerWindowID"
                 onget="return this._outerWindowID"
                 readonly="true"/>
 
       <property name="autoCompletePopup"
                 onget="return document.getElementById(this.getAttribute('autocompletepopup'))"
                 readonly="true"/>