Bug 1187419 - Make sure SettingsRequestManager is only loaded in parent. r=gwagner

dom/settings/SettingsRequestManager.jsm

@@ -6,6 +6,7 @@
 
 const Cc = Components.classes;
 const Ci = Components.interfaces;
+const Cr = Components.results;
 const Cu = Components.utils;
 
 Cu.importGlobalProperties(['File']);
@@ -39,6 +40,9 @@ function debug(s) {
   dump("-*- SettingsRequestManager: " + s + "\n");
 }
 
+let inParent = Cc["@mozilla.org/xre/app-info;1"].getService(Ci.nsIXULRuntime)
+                  .processType == Ci.nsIXULRuntime.PROCESS_TYPE_DEFAULT;
+
 const kXpcomShutdownObserverTopic      = "xpcom-shutdown";
 const kInnerWindowDestroyed            = "inner-window-destroyed";
 const kMozSettingsChangedObserverTopic = "mozsettings-changed";
@@ -1210,5 +1214,11 @@ let SettingsRequestManager = {
   }
 };
 
-this.SettingsRequestManager = SettingsRequestManager;
-SettingsRequestManager.init();
+// This code should ALWAYS be living only on the parent side.
+if (!inParent) {
+  debug("SettingsRequestManager should be living on parent side.");
+  throw Cr.NS_ERROR_ABORT;
+} else {
+  this.SettingsRequestManager = SettingsRequestManager;
+  SettingsRequestManager.init();
+}