--- a/layout/tools/reftest/b2g_desktop.py
+++ b/layout/tools/reftest/b2g_desktop.py
@@ -36,17 +36,17 @@ class B2GDesktopReftest(RefTest):
         self.test_script = os.path.join(here, 'b2g_start_script.js')
         self.timeout = None
 
     def run_marionette_script(self):
         self.marionette = Marionette(**self.marionette_args)
         assert(self.marionette.wait_for_port())
         self.marionette.start_session()
         if self.build_type == "mulet":
-            self._wait_for_homescreen(timeout=15)
+            self._wait_for_homescreen(timeout=300)
             self._unlockScreen()
         self.marionette.set_context(self.marionette.CONTEXT_CHROME)
 
         if os.path.isfile(self.test_script):
             f = open(self.test_script, 'r')
             self.test_script = f.read()
             f.close()
         self.marionette.execute_script(self.test_script)

--- a/layout/tools/reftest/reftest.js
+++ b/layout/tools/reftest/reftest.js
@@ -55,16 +55,17 @@ const FOCUS_FILTER_NON_NEEDS_FOCUS_TESTS
 var gFocusFilterMode = FOCUS_FILTER_ALL_TESTS;
 
 // "<!--CLEAR-->"
 const BLANK_URL_FOR_CLEARING = "data:text/html;charset=UTF-8,%3C%21%2D%2DCLEAR%2D%2D%3E";
 
 var gBrowser;
 // Are we testing web content loaded in a separate process?
 var gBrowserIsRemote;           // bool
+var gB2GisMulet;                // bool
 // Are we using <iframe mozbrowser>?
 var gBrowserIsIframe;           // bool
 var gBrowserMessageManager;
 var gCanvas1, gCanvas2;
 // gCurrentCanvas is non-null between InitCurrentCanvasWithSnapshot and the next
 // RecordResult.
 var gCurrentCanvas = null;
 var gURLs;
@@ -244,16 +245,22 @@ this.OnRefTestLoad = function OnRefTestL
                 getService(Components.interfaces.nsIPrefBranch);
     try {
         gBrowserIsRemote = prefs.getBoolPref("browser.tabs.remote.autostart");
     } catch (e) {
         gBrowserIsRemote = false;
     }
 
     try {
+        gB2GisMulet = prefs.getBoolPref("b2g.is_mulet");
+    } catch (e) {
+        gB2GisMulet = false;
+    }
+
+    try {
       gBrowserIsIframe = prefs.getBoolPref("reftest.browser.iframe.enabled");
     } catch (e) {
       gBrowserIsIframe = false;
     }
 
     if (win === undefined || win == null) {
       win = window;
     }
@@ -725,16 +732,17 @@ function BuildConditionSandbox(aURL) {
         }
 
         return testPluginIsOOP;
     };
 
     // Tests shouldn't care about this except for when they need to
     // crash the content process
     sandbox.browserIsRemote = gBrowserIsRemote;
+    sandbox.Mulet = gB2GisMulet;
 
     try {
         sandbox.asyncPanZoom = prefs.getBoolPref("layers.async-pan-zoom.enabled");
     } catch (e) {
         sandbox.asyncPanZoom = false;
     }
 
     if (!gDumpedConditionSandbox) {