--- a/layout/tools/reftest/reftestcommandline.py
+++ b/layout/tools/reftest/reftestcommandline.py
@@ -405,17 +405,17 @@ class RemoteArgumentsParser(ReftestArgum
                           xrePath="",
                           utilityPath="",
                           localLogName=None)
 
         self.add_argument("--adbpath",
                           action="store",
                           type=str,
                           dest="adb_path",
-                          default="adb",
+                          default=None,
                           help="path to adb")
 
         self.add_argument("--deviceSerial",
                           action="store",
                           type=str,
                           dest="deviceSerial",
                           help="adb serial number of remote device to test")
 

--- a/layout/tools/reftest/remotereftest.py
+++ b/layout/tools/reftest/remotereftest.py
@@ -144,17 +144,17 @@ class RemoteReftest(RefTest):
         self.run_by_manifest = False
         self.scriptDir = scriptDir
         self.localLogName = options.localLogName
 
         verbose = False
         if options.log_tbpl_level == 'debug' or options.log_mach_level == 'debug':
             verbose = True
             print "set verbose!"
-        self.device = ADBAndroid(adb=options.adb_path,
+        self.device = ADBAndroid(adb=options.adb_path or 'adb',
                                  device=options.deviceSerial,
                                  test_root=options.remoteTestRoot,
                                  verbose=verbose)
 
         if options.remoteTestRoot is None:
             options.remoteTestRoot = posixpath.join(self.device.test_root, "reftest")
         options.remoteProfile = posixpath.join(options.remoteTestRoot, "profile")
         options.remoteLogFile = posixpath.join(options.remoteTestRoot, "reftest.log")

--- a/testing/mochitest/mochitest_options.py
+++ b/testing/mochitest/mochitest_options.py
@@ -850,17 +850,17 @@ class AndroidArguments(ArgumentContainer
     args = [
         [["--deviceSerial"],
          {"dest": "deviceSerial",
           "help": "ip address of remote device to test",
           "default": None,
           }],
         [["--adbpath"],
          {"dest": "adbPath",
-          "default": "adb",
+          "default": None,
           "help": "Path to adb binary.",
           "suppress": True,
           }],
         [["--remote-webserver"],
          {"dest": "remoteWebServer",
           "default": None,
           "help": "ip address where the remote web server is hosted at",
           }],

--- a/testing/mochitest/rungeckoview.py
+++ b/testing/mochitest/rungeckoview.py
@@ -34,34 +34,34 @@ class GeckoviewOptions(OptionParser):
                         default="org.mozilla.geckoview_example",
                         help="geckoview_example package name")
         self.add_option("--deviceSerial",
                         action="store", type="string", dest="deviceSerial",
                         default=None,
                         help="serial ID of remote device to test")
         self.add_option("--adbpath",
                         action="store", type="string", dest="adbPath",
-                        default="adb",
+                        default=None,
                         help="Path to adb binary.")
         self.add_option("--remoteTestRoot",
                         action="store", type="string", dest="remoteTestRoot",
                         default=None,
                         help="remote directory to use as test root \
                               (eg. /mnt/sdcard/tests or /data/local/tests)")
 
 
 class GeckoviewTestRunner:
     """
        A quick-and-dirty test harness to verify the geckoview_example
        app starts without crashing.
     """
 
     def __init__(self, log, options):
         self.log = log
-        self.device = ADBAndroid(adb=options.adbPath,
+        self.device = ADBAndroid(adb=options.adbPath or 'adb',
                                  device=options.deviceSerial,
                                  test_root=options.remoteTestRoot)
         self.options = options
         self.appname = self.options.app.split('/')[-1]
         self.logcat = None
         self.build_profile()
         self.log.debug("options=%s" % vars(options))
 

--- a/testing/mochitest/runrobocop.py
+++ b/testing/mochitest/runrobocop.py
@@ -42,17 +42,17 @@ class RobocopTestRunner(MochitestDesktop
         """
            Simple one-time initialization.
         """
         MochitestDesktop.__init__(self, options.flavor, vars(options))
 
         verbose = False
         if options.log_tbpl_level == 'debug' or options.log_mach_level == 'debug':
             verbose = True
-        self.device = ADBAndroid(adb=options.adbPath,
+        self.device = ADBAndroid(adb=options.adbPath or 'adb',
                                  device=options.deviceSerial,
                                  test_root=options.remoteTestRoot,
                                  verbose=verbose)
 
         # Check that Firefox is installed
         expected = options.app.split('/')[-1]
         if not self.device.is_app_installed(expected):
             raise Exception("%s is not installed on this device" % expected)

--- a/testing/mochitest/runtestsremote.py
+++ b/testing/mochitest/runtestsremote.py
@@ -35,17 +35,17 @@ class MochiRemote(MochitestDesktop):
             verbose = True
         if hasattr(options, 'log'):
             delattr(options, 'log')
 
         self.certdbNew = True
         self.chromePushed = False
         self.mozLogName = "moz.log"
 
-        self.device = ADBAndroid(adb=options.adbPath,
+        self.device = ADBAndroid(adb=options.adbPath or 'adb',
                                  device=options.deviceSerial,
                                  test_root=options.remoteTestRoot,
                                  verbose=verbose)
 
         if options.remoteTestRoot is None:
             options.remoteTestRoot = self.device.test_root
         options.dumpOutputDirectory = options.remoteTestRoot
         self.remoteLogFile = posixpath.join(options.remoteTestRoot, "logs", "mochitest.log")

--- a/testing/remotecppunittests.py
+++ b/testing/remotecppunittests.py
@@ -23,17 +23,17 @@ except ImportError:
     build_obj = None
 
 
 class RemoteCPPUnitTests(cppunittests.CPPUnitTests):
 
     def __init__(self, options, progs):
         cppunittests.CPPUnitTests.__init__(self)
         self.options = options
-        self.device = ADBAndroid(adb=options.adb_path,
+        self.device = ADBAndroid(adb=options.adb_path or 'adb',
                                  device=options.device_serial,
                                  test_root=options.remote_test_root)
         self.remote_test_root = posixpath.join(self.device.test_root, "cppunittests")
         self.remote_bin_dir = posixpath.join(self.remote_test_root, "b")
         self.remote_tmp_dir = posixpath.join(self.remote_test_root, "tmp")
         self.remote_home_dir = posixpath.join(self.remote_test_root, "h")
         if options.setup:
             self.setup_bin(progs)
@@ -170,17 +170,17 @@ class RemoteCPPUnittestOptions(cppunitte
         self.add_option("--deviceSerial", action="store",
                         type="string", dest="device_serial",
                         help="serial ID of device")
         defaults["device_serial"] = None
 
         self.add_option("--adbPath", action="store",
                         type="string", dest="adb_path",
                         help="Path to adb")
-        defaults["adb_path"] = "adb"
+        defaults["adb_path"] = None
 
         self.add_option("--noSetup", action="store_false",
                         dest="setup",
                         help="do not copy any files to device (to be used only if "
                         "device is already setup)")
         defaults["setup"] = True
 
         self.add_option("--localLib", action="store",

--- a/testing/xpcshell/remotexpcshelltests.py
+++ b/testing/xpcshell/remotexpcshelltests.py
@@ -236,17 +236,17 @@ class XPCShellRemote(xpcshell.XPCShellTe
 
     def __init__(self, options, log):
         xpcshell.XPCShellTests.__init__(self, log)
 
         self.options = options
         verbose = False
         if options['log_tbpl_level'] == 'debug' or options['log_mach_level'] == 'debug':
             verbose = True
-        self.device = ADBAndroid(adb=options['adbPath'],
+        self.device = ADBAndroid(adb=options['adbPath'] or 'adb',
                                  device=options['deviceSerial'],
                                  test_root=options['remoteTestRoot'],
                                  verbose=verbose)
         self.remoteTestRoot = posixpath.join(self.device.test_root, "xpc")
         # Add Android version (SDK level) to mozinfo so that manifest entries
         # can be conditional on android_version.
         mozinfo.info['android_version'] = self.device.version
 

--- a/testing/xpcshell/xpcshellcommandline.py
+++ b/testing/xpcshell/xpcshellcommandline.py
@@ -142,17 +142,17 @@ def add_remote_arguments(parser):
 
     parser.add_argument("--apk", action="store", type=str, dest="localAPK",
                         help="local path to Fennec APK")
 
     parser.add_argument("--deviceSerial", action="store", type=str, dest="deviceSerial",
                         help="serial ID of device")
 
     parser.add_argument("--adbPath", action="store", type=str, dest="adbPath",
-                        default="adb",
+                        default=None,
                         help="Path to adb")
 
     parser.add_argument("--noSetup", action="store_false", dest="setup", default=True,
                         help="do not copy any files to device (to be used only if "
                              "device is already setup)")
 
     parser.add_argument("--local-lib-dir", action="store", type=str, dest="localLib",
                         help="local path to library directory")