Bug 600441 - "[regression] Escape key goes back in history when Form Helper is opened" [r=mark.finkle]

mobile/chrome/content/bindings.xml

@@ -1397,6 +1397,8 @@
         ]]></body>
       </method>
 
+      <property name="isActive" onget="return !this._spacer.hidden;"/>
+
       <field name="_model">null</field>
       <method name="show">
         <parameter name="aModel" />

mobile/chrome/content/browser-ui.js

@@ -730,6 +730,13 @@ var BrowserUI = {
       return;
     }
 
+    // Check content helper
+    let contentHelper = document.getElementById("content-navigator");
+    if (contentHelper.isActive) {
+      contentHelper.hide();
+      return;
+    }
+
     // Only if there are no dialogs, popups, or panels open
     let tab = Browser.selectedTab;
     let browser = tab.browser;