diff --git a/testing/mochitest/jar.mn b/testing/mochitest/jar.mn
index 7748cd568cf..cdb08af3523 100644
--- a/testing/mochitest/jar.mn
+++ b/testing/mochitest/jar.mn
@@ -15,6 +15,7 @@ mochikit.jar:
   content/server.js (server.js)
   content/chunkifyTests.js (chunkifyTests.js)
   content/manifestLibrary.js (manifestLibrary.js)
+  content/nested_setup.js (nested_setup.js)
   content/dynamic/getMyDirectory.sjs (dynamic/getMyDirectory.sjs)
   content/static/harness.css (static/harness.css)
   content/tests/SimpleTest/ChromePowers.js (tests/SimpleTest/ChromePowers.js)
diff --git a/testing/mochitest/mach_commands.py b/testing/mochitest/mach_commands.py
index a8df2ef54cf..8f6b3e2f8ec 100644
--- a/testing/mochitest/mach_commands.py
+++ b/testing/mochitest/mach_commands.py
@@ -191,7 +191,7 @@ class MochitestRunner(MozbuildObject):
         rerun_failures=False, no_autorun=False, repeat=0, run_until_failure=False,
         slow=False, chunk_by_dir=0, total_chunks=None, this_chunk=None, extraPrefs=[],
         jsdebugger=False, debug_on_failure=False, start_at=None, end_at=None,
-        e10s=False, strict_content_sandbox=False, dmd=False, dump_output_directory=None,
+        e10s=False, strict_content_sandbox=False, nested_oop=False, dmd=False, dump_output_directory=None,
         dump_about_memory_after_test=False, dump_dmd_after_test=False,
         install_extension=None, quiet=False, environment=[], app_override=None, bisectChunk=None, runByDir=False,
         useTestMediaDevices=False, timeout=None, **kwargs):
@@ -314,6 +314,7 @@ class MochitestRunner(MozbuildObject):
         options.endAt = end_at
         options.e10s = e10s
         options.strictContentSandbox = strict_content_sandbox
+        options.nested_oop = nested_oop
         options.dumpAboutMemoryAfterTest = dump_about_memory_after_test
         options.dumpDMDAfterTest = dump_dmd_after_test
         options.dumpOutputDirectory = dump_output_directory
@@ -508,6 +509,10 @@ def MochitestCommand(func):
         help='Run tests with a more strict content sandbox (Windows only).')
     func = strict_content_sandbox(func)
 
+    this_chunk = CommandArgument('--nested-oop', action='store_true',
+        help='Run tests with nested oop preferences and test filtering enabled.')
+    func = this_chunk(func)
+
     dmd = CommandArgument('--dmd', action='store_true',
         help='Run tests with DMD active.')
     func = dmd(func)
diff --git a/testing/mochitest/mochitest_options.py b/testing/mochitest/mochitest_options.py
index 309a816c266..6da11fb3722 100644
--- a/testing/mochitest/mochitest_options.py
+++ b/testing/mochitest/mochitest_options.py
@@ -369,6 +369,12 @@ class MochitestOptions(optparse.OptionParser):
           "dest": "strictContentSandbox",
           "help": "Run tests with a more strict content sandbox (Windows only).",
         }],
+        [["--nested-oop"],
+        { "action": "store_true",
+          "default": False,
+          "dest": "nested_oop",
+          "help": "Run tests with nested-oop preferences and test filtering enabled.",
+        }],
         [["--dmd-path"],
          { "action": "store",
            "default": None,
@@ -481,6 +487,7 @@ class MochitestOptions(optparse.OptionParser):
 
         mozinfo.update({"e10s": options.e10s}) # for test manifest parsing.
         mozinfo.update({"strictContentSandbox": options.strictContentSandbox}) # for test manifest parsing.
+        mozinfo.update({"nested_oop": options.nested_oop}) # for test manifest parsing.
 
         if options.app is None:
             if build_obj is not None:
diff --git a/testing/mochitest/moz.build b/testing/mochitest/moz.build
index 2b7f0f8398c..99c43193121 100644
--- a/testing/mochitest/moz.build
+++ b/testing/mochitest/moz.build
@@ -61,6 +61,7 @@ TEST_HARNESS_FILES.testing.mochitest += [
     'manifest.webapp',
     'manifestLibrary.js',
     'mochitest_options.py',
+    'nested_setup.js',
     'pywebsocket_wrapper.py',
     'redirect.html',
     'runtests.py',
diff --git a/testing/mochitest/nested_setup.js b/testing/mochitest/nested_setup.js
new file mode 100644
index 00000000000..f7fc13e1fbf
--- /dev/null
+++ b/testing/mochitest/nested_setup.js
@@ -0,0 +1,30 @@
+
+var gTestURL = '';
+
+function addPermissions()
+{
+  SpecialPowers.pushPermissions(
+    [{ type: "browser", allow: true, context: document }],
+    addPreferences);
+}
+
+function addPreferences()
+{
+  SpecialPowers.pushPrefEnv(
+    {"set": [["dom.mozBrowserFramesEnabled", true]]},
+    insertFrame);
+}
+
+
+function insertFrame()
+{
+  var iframe = document.createElement('iframe');
+  iframe.id = 'nested-parent-frame';
+  iframe.width = "100%";
+  iframe.height = "100%";
+  iframe.scoring = "no";
+  iframe.setAttribute("remote", "true");
+  iframe.setAttribute("mozbrowser", "true");
+  iframe.src = gTestURL;
+  document.getElementById("holder-div").appendChild(iframe);
+}
\ No newline at end of file
diff --git a/testing/mochitest/runtests.py b/testing/mochitest/runtests.py
index 8967e949291..72f97f458b8 100644
--- a/testing/mochitest/runtests.py
+++ b/testing/mochitest/runtests.py
@@ -421,6 +421,7 @@ class MochitestUtilsMixin(object):
 
   # Path to the test script on the server
   TEST_PATH = "tests"
+  NESTED_OOP_TEST_PATH = "nested_oop"
   CHROME_PATH = "redirect.html"
   urlOpts = []
   log = None
@@ -652,6 +653,8 @@ class MochitestUtilsMixin(object):
       testURL = "/".join([testHost, self.CHROME_PATH])
     elif options.browserChrome or options.jetpackPackage or options.jetpackAddon:
       testURL = "about:blank"
+    if options.nested_oop:
+      testURL = "/".join([testHost, self.NESTED_OOP_TEST_PATH])
     return testURL
 
   def buildTestPath(self, options, testsToFilter=None, disabled=True):
@@ -1161,6 +1164,7 @@ class Mochitest(MochitestUtilsMixin):
     options.extraPrefs.append("browser.tabs.remote.autostart=%s" % ('true' if options.e10s else 'false'))
     if options.strictContentSandbox:
         options.extraPrefs.append("security.sandbox.windows.content.moreStrict=true")
+    options.extraPrefs.append("dom.ipc.tabs.nested.enabled=%s" % ('true' if options.nested_oop else 'false'))
 
     # get extensions to install
     extensions = self.getExtensionsToInstall(options)
diff --git a/testing/mochitest/server.js b/testing/mochitest/server.js
index c2a2b62fa98..98b605de29f 100644
--- a/testing/mochitest/server.js
+++ b/testing/mochitest/server.js
@@ -210,6 +210,7 @@ function createMochitestServer(serverBasePath)
   server.registerDirectory("/", serverBasePath);
   server.registerPathHandler("/server/shutdown", serverShutdown);
   server.registerPathHandler("/server/debug", serverDebug);
+  server.registerPathHandler("/nested_oop", nestedTest);
   server.registerContentType("sjs", "sjs"); // .sjs == CGI-like functionality
   server.registerContentType("jar", "application/x-jar");
   server.registerContentType("ogg", "application/ogg");
@@ -598,6 +599,31 @@ function convertManifestToTestLinks(root, manifest)
           paths.length];
 }
 
+/**
+ * Produce a test harness page that has one remote iframe
+ */
+function nestedTest(metadata, response)
+{
+  response.setStatusLine("1.1", 200, "OK");
+  response.setHeader("Content-type", "text/html;charset=utf-8", false);
+  response.write(
+    HTML(
+      HEAD(
+        TITLE("Mochitest | ", metadata.path),
+        LINK({rel: "stylesheet",
+              type: "text/css", href: "/static/harness.css"}),
+        SCRIPT({type: "text/javascript",
+                src: "/nested_setup.js"}),
+        SCRIPT({type: "text/javascript"},
+               "window.onload = addPermissions; gTestURL = '/tests?" + metadata.queryString + "';")
+        ),
+      BODY(
+        DIV({class: "container"},
+          DIV({class: "frameholder", id: "holder-div"})
+        )
+        )));
+}
+
 /**
  * Produce a test harness page containing all the test cases
  * below it, recursively.
diff --git a/testing/specialpowers/content/specialpowers.js b/testing/specialpowers/content/specialpowers.js
index b728cedfdad..589899cb7b5 100644
--- a/testing/specialpowers/content/specialpowers.js
+++ b/testing/specialpowers/content/specialpowers.js
@@ -5,6 +5,31 @@
  * order to be used as a replacement for UniversalXPConnect
  */
 
+Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
+Components.utils.import("resource://gre/modules/Services.jsm");
+
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+
+const CHILD_SCRIPT = "chrome://specialpowers/content/specialpowers.js";
+const CHILD_SCRIPT_API = "chrome://specialpowers/content/specialpowersAPI.js";
+const CHILD_LOGGER_SCRIPT = "chrome://specialpowers/content/MozillaLogger.js";
+
+// All messages sent to observer should be listed here.
+const SP_SYNC_MESSAGES = ["SPChromeScriptMessage",
+                          "SPLoadChromeScript",
+                          "SPObserverService",
+                          "SPPermissionManager",
+                          "SPPrefService",
+                          "SPProcessCrashService",
+                          "SPSetTestPluginEnabledState",
+                          "SPWebAppService"];
+
+const SP_ASYNC_MESSAGES = ["SpecialPowers.Focus",
+                           "SpecialPowers.Quit",
+                           "SPPingService",
+                           "SPQuotaManager"];
+
 function SpecialPowers(window) {
   this.window = Components.utils.getWeakReference(window);
   this._windowID = window.QueryInterface(Components.interfaces.nsIInterfaceRequestor)
@@ -23,6 +48,8 @@ function SpecialPowers(window) {
       }});
   this._pongHandlers = [];
   this._messageListener = this._messageReceived.bind(this);
+  this._nestedFrameInjected = false;
+  this._grandChildFrameMM = null;
   addMessageListener("SPPingService", this._messageListener);
   let (self = this) {
     Services.obs.addObserver(function onInnerWindowDestroyed(subject, topic, data) {
@@ -37,6 +64,40 @@ function SpecialPowers(window) {
         }
       }
     }, "inner-window-destroyed", false);
+    Services.obs.addObserver(function onRemoteBrowserShown(subject, topic, data) {
+      let frameLoader = subject;
+
+      // get a ref to the app <iframe>
+      frameLoader.QueryInterface(Ci.nsIFrameLoader);
+      let frame = frameLoader.ownerElement;
+      let mm = frame.QueryInterface(Ci.nsIFrameLoaderOwner).frameLoader.messageManager;
+      var frameId = frame.getAttribute('id');
+
+      if (frameId === "nested-parent-frame" && !self._nestedFrameInjected) {
+        Services.obs.removeObserver(onRemoteBrowserShown, "remote-browser-shown");
+        self._grandChildFrameMM = mm;
+        mm.loadFrameScript(CHILD_LOGGER_SCRIPT, true);
+        mm.loadFrameScript(CHILD_SCRIPT_API, true);
+        mm.loadFrameScript(CHILD_SCRIPT, true);
+
+        SP_SYNC_MESSAGES.forEach(function (msgname) {
+          mm.addMessageListener(msgname, function (msg) {
+            return self._sendSyncMessage(msgname, msg.data)[0];
+          });
+        });
+        SP_ASYNC_MESSAGES.forEach(function (msgname) {
+          mm.addMessageListener(msgname, function (msg) {
+            self._sendAsyncMessage(msgname, msg.data);
+          });
+        });
+        mm.addMessageListener("SPPAddNestedMessageListener", function(msg) {
+          self._addMessageListener(msg.json.name, function(aMsg) {
+            mm.sendAsyncMessage(aMsg.name, aMsg.data);
+            });
+          });
+        self._nestedFrameInjected = true;
+      }
+    }, "remote-browser-shown", false);
   }
 }
 
@@ -50,15 +111,22 @@ SpecialPowers.prototype.DOMWindowUtils = undefined;
 SpecialPowers.prototype.Components = undefined;
 
 SpecialPowers.prototype._sendSyncMessage = function(msgname, msg) {
+  if (SP_SYNC_MESSAGES.indexOf(msgname) == -1) {
+    throw new Error("Unexpected SP message: " + msgname);
+  }
   return sendSyncMessage(msgname, msg);
 };
 
 SpecialPowers.prototype._sendAsyncMessage = function(msgname, msg) {
+  if (SP_ASYNC_MESSAGES.indexOf(msgname) == -1) {
+    throw new Error("Unexpected SP message: " + msgname);
+  }
   sendAsyncMessage(msgname, msg);
 };
 
 SpecialPowers.prototype._addMessageListener = function(msgname, listener) {
   addMessageListener(msgname, listener);
+  sendAsyncMessage("SPPAddNestedMessageListener", { name: msgname });
 };
 
 SpecialPowers.prototype._removeMessageListener = function(msgname, listener) {
@@ -91,6 +159,9 @@ SpecialPowers.prototype._messageReceived = function(aMessage) {
         if (handler) {
           handler();
         }
+        if (this._grandChildFrameMM) {
+          this._grandChildFrameMM.sendAsyncMessage("SPPingService", { op: "pong" });
+        }
       }
       break;
   }
diff --git a/testing/specialpowers/content/specialpowersAPI.js b/testing/specialpowers/content/specialpowersAPI.js
index 8355c9d5173..ee32fee7793 100644
--- a/testing/specialpowers/content/specialpowersAPI.js
+++ b/testing/specialpowers/content/specialpowersAPI.js
@@ -213,8 +213,9 @@ function unwrapPrivileged(x) {
   if (!isWrapper(x))
     throw "Trying to unwrap a non-wrapped object!";
 
-  // Unwrap.
-  return x.SpecialPowers_wrappedObject;
+  var obj = x.SpecialPowers_wrappedObject;
+  // unwrapped.
+  return obj;
 };
 
 function crawlProtoChain(obj, fn) {
@@ -662,10 +663,10 @@ SpecialPowersAPI.prototype = {
    * we don't SpecialPowers-wrap Components.interfaces, because it's available
    * to untrusted content, and wrapping it confuses QI and identity checks.
    */
-  get Cc() { return wrapPrivileged(this.getFullComponents()).classes; },
+  get Cc() { return wrapPrivileged(this.getFullComponents().classes); },
   get Ci() { return this.Components.interfaces; },
-  get Cu() { return wrapPrivileged(this.getFullComponents()).utils; },
-  get Cr() { return wrapPrivileged(this.Components).results; },
+  get Cu() { return wrapPrivileged(this.getFullComponents().utils); },
+  get Cr() { return wrapPrivileged(this.Components.results); },
 
   /*
    * SpecialPowers.getRawComponents() allows content to get a reference to a