new file mode 100644
--- /dev/null
+++ b/testing/mochitest/__init__.py
@@ -0,0 +1,3 @@
+# 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/.

--- a/testing/mochitest/mach_commands.py
+++ b/testing/mochitest/mach_commands.py
@@ -1,17 +1,16 @@
 # 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 absolute_import, unicode_literals
 
 from argparse import Namespace
 from collections import defaultdict
-from itertools import chain
 import logging
 import os
 import sys
 import warnings
 
 from mozbuild.base import (
     MachCommandBase,
     MachCommandConditions as conditions,
@@ -71,71 +70,17 @@ Please check spelling and make sure the 
 
 NOW_RUNNING = '''
 ######
 ### Now running mochitest-{}.
 ######
 '''
 
 
-# Maps test flavors to data needed to run them
-ALL_FLAVORS = {
-    'mochitest': {
-        'suite': 'plain',
-        'aliases': ('plain', 'mochitest'),
-        'enabled_apps': ('firefox', 'android'),
-        'extra_args': {
-            'flavor': 'plain',
-        }
-    },
-    'chrome': {
-        'suite': 'chrome',
-        'aliases': ('chrome', 'mochitest-chrome'),
-        'enabled_apps': ('firefox', 'android'),
-        'extra_args': {
-            'flavor': 'chrome',
-        }
-    },
-    'browser-chrome': {
-        'suite': 'browser',
-        'aliases': ('browser', 'browser-chrome', 'mochitest-browser-chrome', 'bc'),
-        'enabled_apps': ('firefox',),
-        'extra_args': {
-            'flavor': 'browser',
-        }
-    },
-    'jetpack-package': {
-        'suite': 'jetpack-package',
-        'aliases': ('jetpack-package', 'mochitest-jetpack-package', 'jpp'),
-        'enabled_apps': ('firefox',),
-        'extra_args': {
-            'flavor': 'jetpack-package',
-        }
-    },
-    'jetpack-addon': {
-        'suite': 'jetpack-addon',
-        'aliases': ('jetpack-addon', 'mochitest-jetpack-addon', 'jpa'),
-        'enabled_apps': ('firefox',),
-        'extra_args': {
-            'flavor': 'jetpack-addon',
-        }
-    },
-    'a11y': {
-        'suite': 'a11y',
-        'aliases': ('a11y', 'mochitest-a11y', 'accessibility'),
-        'enabled_apps': ('firefox',),
-        'extra_args': {
-            'flavor': 'a11y',
-        }
-    },
-}
-
 SUPPORTED_APPS = ['firefox', 'android']
-SUPPORTED_FLAVORS = list(chain.from_iterable([f['aliases'] for f in ALL_FLAVORS.values()]))
-CANONICAL_FLAVORS = sorted([f['aliases'][0] for f in ALL_FLAVORS.values()])
 
 parser = None
 
 
 class MochitestRunner(MozbuildObject):
 
     """Easily run mochitests.
 
@@ -329,21 +274,19 @@ def verify_host_bin():
 
 
 @CommandProvider
 class MachCommands(MachCommandBase):
     @Command('mochitest', category='testing',
              conditions=[is_buildapp_in(*SUPPORTED_APPS)],
              description='Run any flavor of mochitest (integration test).',
              parser=setup_argument_parser)
-    @CommandArgument('-f', '--flavor',
-                     metavar='{{{}}}'.format(', '.join(CANONICAL_FLAVORS)),
-                     choices=SUPPORTED_FLAVORS,
-                     help='Only run tests of this flavor.')
     def run_mochitest_general(self, flavor=None, test_objects=None, resolve_tests=True, **kwargs):
+        from mochitest.mochitest_options import ALL_FLAVORS
+
         buildapp = None
         for app in SUPPORTED_APPS:
             if is_buildapp_in(app)(self):
                 buildapp = app
                 break
 
         flavors = None
         if flavor:

--- a/testing/mochitest/mochitest_options.py
+++ b/testing/mochitest/mochitest_options.py
@@ -1,15 +1,16 @@
 # 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 abc import ABCMeta, abstractmethod, abstractproperty
 from argparse import ArgumentParser, SUPPRESS
 from distutils.util import strtobool
+from itertools import chain
 from urlparse import urlparse
 import json
 import os
 import tempfile
 
 from mozdevice import DroidADB, DroidSUT
 from mozprofile import DEFAULT_PORTS
 import mozinfo
@@ -25,16 +26,71 @@ try:
         MachCommandConditions as conditions,
     )
     build_obj = MozbuildObject.from_environment(cwd=here)
 except ImportError:
     build_obj = None
     conditions = None
 
 
+# Maps test flavors to data needed to run them
+ALL_FLAVORS = {
+    'mochitest': {
+        'suite': 'plain',
+        'aliases': ('plain', 'mochitest'),
+        'enabled_apps': ('firefox', 'android'),
+        'extra_args': {
+            'flavor': 'plain',
+        }
+    },
+    'chrome': {
+        'suite': 'chrome',
+        'aliases': ('chrome', 'mochitest-chrome'),
+        'enabled_apps': ('firefox', 'android'),
+        'extra_args': {
+            'flavor': 'chrome',
+        }
+    },
+    'browser-chrome': {
+        'suite': 'browser',
+        'aliases': ('browser', 'browser-chrome', 'mochitest-browser-chrome', 'bc'),
+        'enabled_apps': ('firefox',),
+        'extra_args': {
+            'flavor': 'browser',
+        }
+    },
+    'jetpack-package': {
+        'suite': 'jetpack-package',
+        'aliases': ('jetpack-package', 'mochitest-jetpack-package', 'jpp'),
+        'enabled_apps': ('firefox',),
+        'extra_args': {
+            'flavor': 'jetpack-package',
+        }
+    },
+    'jetpack-addon': {
+        'suite': 'jetpack-addon',
+        'aliases': ('jetpack-addon', 'mochitest-jetpack-addon', 'jpa'),
+        'enabled_apps': ('firefox',),
+        'extra_args': {
+            'flavor': 'jetpack-addon',
+        }
+    },
+    'a11y': {
+        'suite': 'a11y',
+        'aliases': ('a11y', 'mochitest-a11y', 'accessibility'),
+        'enabled_apps': ('firefox',),
+        'extra_args': {
+            'flavor': 'a11y',
+        }
+    },
+}
+SUPPORTED_FLAVORS = list(chain.from_iterable([f['aliases'] for f in ALL_FLAVORS.values()]))
+CANONICAL_FLAVORS = sorted([f['aliases'][0] for f in ALL_FLAVORS.values()])
+
+
 def get_default_valgrind_suppression_files():
     # We are trying to locate files in the source tree.  So if we
     # don't know where the source tree is, we must give up.
     #
     # When this is being run by |mach mochitest --valgrind ...|, it is
     # expected that |build_obj| is not None, and so the logic below will
     # select the correct suppression files.
     #
@@ -80,33 +136,31 @@ class ArgumentContainer():
 
     def get_full_path(self, path, cwd):
         """Get an absolute path relative to cwd."""
         return os.path.normpath(os.path.join(cwd, os.path.expanduser(path)))
 
 
 class MochitestArguments(ArgumentContainer):
     """General mochitest arguments."""
-
-    FLAVORS = ('a11y', 'browser', 'chrome', 'jetpack-addon', 'jetpack-package', 'plain')
     LOG_LEVELS = ("DEBUG", "INFO", "WARNING", "ERROR", "FATAL")
 
     args = [
         [["test_paths"],
          {"nargs": "*",
           "metavar": "TEST",
           "default": [],
           "help": "Test to run. Can be a single test file or a directory of tests "
                   "(to run recursively). If omitted, the entire suite is run.",
           }],
         [["-f", "--flavor"],
-         {"default": "plain",
-          "choices": FLAVORS,
-          "help": "Mochitest flavor to run, one of {}. Defaults to 'plain'.".format(FLAVORS),
-          "suppress": build_obj is not None,
+         {"choices": SUPPORTED_FLAVORS,
+          "metavar": "{{{}}}".format(', '.join(CANONICAL_FLAVORS)),
+          "default": None,
+          "help": "Only run tests of this flavor.",
           }],
         [["--keep-open"],
          {"nargs": "?",
           "type": strtobool,
           "const": "true",
           "default": None,
           "help": "Always keep the browser open after tests complete. Or always close the "
                   "browser with --keep-open=false",
@@ -578,16 +632,19 @@ class MochitestArguments(ArgumentContain
                 options.app = build_obj.get_binary_path(where='staged-package')
 
             options.app = self.get_full_path(options.app, parser.oldcwd)
             if not os.path.exists(options.app):
                 parser.error("Error: Path {} doesn't exist. Are you executing "
                              "$objdir/_tests/testing/mochitest/runtests.py?".format(
                                  options.app))
 
+        if options.flavor is None:
+            options.flavor = 'plain'
+
         if options.gmp_path is None and options.app and build_obj:
             # Need to fix the location of gmp_fake which might not be shipped in the binary
             gmp_modules = (
                 ('gmp-fake', '1.0'),
                 ('gmp-clearkey', '0.1'),
                 ('gmp-fakeopenh264', '1.0')
             )
             options.gmp_path = os.pathsep.join(