diff -r 000000000000 -r 6474c204b198 layout/tools/reftest/b2g_desktop.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/layout/tools/reftest/b2g_desktop.py	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,175 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this file,
+# You can obtain one at http://mozilla.org/MPL/2.0/.
+from __future__ import print_function, unicode_literals
+
+import json
+import os
+import signal
+import sys
+import threading
+
+here = os.path.abspath(os.path.dirname(__file__))
+
+from runreftest import RefTest, ReftestOptions
+
+from marionette import Marionette
+from mozprocess import ProcessHandler
+from mozrunner import FirefoxRunner
+import mozinfo
+import mozlog
+
+log = mozlog.getLogger('REFTEST')
+
+class B2GDesktopReftest(RefTest):
+    def __init__(self, marionette):
+        RefTest.__init__(self)
+        self.last_test = os.path.basename(__file__)
+        self.marionette = marionette
+        self.profile = None
+        self.runner = None
+        self.test_script = os.path.join(here, 'b2g_start_script.js')
+        self.timeout = None
+
+    def run_marionette_script(self):
+        assert(self.marionette.wait_for_port())
+        self.marionette.start_session()
+        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)
+
+    def run_tests(self, test_path, options):
+        reftestlist = self.getManifestPath(test_path)
+        if not reftestlist.startswith('file://'):
+            reftestlist = 'file://%s' % reftestlist
+
+        self.profile = self.create_profile(options, reftestlist,
+                                           profile_to_clone=options.profile)
+        env = self.buildBrowserEnv(options, self.profile.profile)
+        kp_kwargs = { 'processOutputLine': [self._on_output],
+                      'onTimeout': [self._on_timeout],
+                      'kill_on_timeout': False }
+
+        if not options.debugger:
+            if not options.timeout:
+                if mozinfo.info['debug']:
+                    options.timeout = 420
+                else:
+                    options.timeout = 300
+            self.timeout = options.timeout + 30.0
+
+        log.info("%s | Running tests: start.", os.path.basename(__file__))
+        cmd, args = self.build_command_line(options.app,
+                            ignore_window_size=options.ignoreWindowSize,
+                            browser_arg=options.browser_arg)
+        self.runner = FirefoxRunner(profile=self.profile,
+                                    binary=cmd,
+                                    cmdargs=args,
+                                    env=env,
+                                    process_class=ProcessHandler,
+                                    symbols_path=options.symbolsPath,
+                                    kp_kwargs=kp_kwargs)
+
+        status = 0
+        try:
+            self.runner.start(outputTimeout=self.timeout)
+            log.info("%s | Application pid: %d",
+                     os.path.basename(__file__),
+                     self.runner.process_handler.pid)
+
+            # kick starts the reftest harness
+            self.run_marionette_script()
+            status = self.runner.wait()
+        finally:
+            self.runner.check_for_crashes(test_name=self.last_test)
+            self.runner.cleanup()
+
+        if status > 0:
+            log.testFail("%s | application terminated with exit code %s",
+                         self.last_test, status)
+        elif status < 0:
+            log.info("%s | application killed with signal %s",
+                         self.last_test, -status)
+
+        log.info("%s | Running tests: end.", os.path.basename(__file__))
+        return status
+
+    def create_profile(self, options, reftestlist, profile_to_clone=None):
+        profile = RefTest.createReftestProfile(self, options, reftestlist,
+                                               profile_to_clone=profile_to_clone)
+
+        prefs = {}
+        # Turn off the locale picker screen
+        prefs["browser.firstrun.show.localepicker"] = False
+        prefs["browser.homescreenURL"] = "app://test-container.gaiamobile.org/index.html"
+        prefs["browser.manifestURL"] = "app://test-container.gaiamobile.org/manifest.webapp"
+        prefs["browser.tabs.remote"] = False
+        prefs["dom.ipc.tabs.disabled"] = False
+        prefs["dom.mozBrowserFramesEnabled"] = True
+        prefs["font.size.inflation.emPerLine"] = 0
+        prefs["font.size.inflation.minTwips"] = 0
+        prefs["network.dns.localDomains"] = "app://test-container.gaiamobile.org"
+        prefs["reftest.browser.iframe.enabled"] = False
+        prefs["reftest.remote"] = False
+        prefs["reftest.uri"] = "%s" % reftestlist
+        # Set a future policy version to avoid the telemetry prompt.
+        prefs["toolkit.telemetry.prompted"] = 999
+        prefs["toolkit.telemetry.notifiedOptOut"] = 999
+
+        # Set the extra prefs.
+        profile.set_preferences(prefs)
+        return profile
+
+    def build_command_line(self, app, ignore_window_size=False,
+                           browser_arg=None):
+        cmd = os.path.abspath(app)
+        args = ['-marionette']
+
+        if browser_arg:
+            args += [browser_arg]
+
+        if not ignore_window_size:
+            args.extend(['--screen', '800x1000'])
+        return cmd, args
+
+    def _on_output(self, line):
+        print(line)
+        # TODO use structured logging
+        if "TEST-START" in line and "|" in line:
+            self.last_test = line.split("|")[1].strip()
+
+    def _on_timeout(self):
+        msg = "%s | application timed out after %s seconds with no output"
+        log.testFail(msg % (self.last_test, self.timeout))
+
+        # kill process to get a stack
+        self.runner.stop(sig=signal.SIGABRT)
+
+
+def run_desktop_reftests(parser, options, args):
+    kwargs = {}
+    if options.marionette:
+        host, port = options.marionette.split(':')
+        kwargs['host'] = host
+        kwargs['port'] = int(port)
+    marionette = Marionette.getMarionetteOrExit(**kwargs)
+
+    reftest = B2GDesktopReftest(marionette)
+
+    options = ReftestOptions.verifyCommonOptions(parser, options, reftest)
+    if options == None:
+        sys.exit(1)
+
+    # add a -bin suffix if b2g-bin exists, but just b2g was specified
+    if options.app[-4:] != '-bin':
+        if os.path.isfile("%s-bin" % options.app):
+            options.app = "%s-bin" % options.app
+
+    if options.desktop and not options.profile:
+        raise Exception("must specify --profile when specifying --desktop")
+
+    sys.exit(reftest.run_tests(args[0], options))