diff --git a/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/base.py b/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/base.py
index 583ca0d6cded..52527599ffbd 100644
--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/base.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/base.py
@@ -83,8 +83,11 @@ class Browser(object):
         """Used for browser-specific setup that happens at the start of a test run"""
         pass
 
+    def settings(self, test):
+        return {}
+
     @abstractmethod
-    def start(self):
+    def start(self, **kwargs):
         """Launch the browser object and get it into a state where is is ready to run tests"""
         pass
 
@@ -126,7 +129,7 @@ class NullBrowser(Browser):
     def __init__(self, logger, **kwargs):
         super(NullBrowser, self).__init__(logger)
 
-    def start(self):
+    def start(self, **kwargs):
         """No-op browser to use in scenarios where the TestRunnerManager shouldn't
         actually own the browser process (e.g. Servo where we start one browser
         per test)"""
diff --git a/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/chrome.py b/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/chrome.py
index 3bd227b32f55..1c08c27922b6 100644
--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/chrome.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/chrome.py
@@ -20,7 +20,7 @@ def check_args(**kwargs):
     require_arg(kwargs, "webdriver_binary")
 
 
-def browser_kwargs(**kwargs):
+def browser_kwargs(test_type, run_info_data, **kwargs):
     return {"binary": kwargs["binary"],
             "webdriver_binary": kwargs["webdriver_binary"],
             "webdriver_args": kwargs.get("webdriver_args")}
@@ -72,7 +72,7 @@ class ChromeBrowser(Browser):
                                          binary=webdriver_binary,
                                          args=webdriver_args)
 
-    def start(self):
+    def start(self, **kwargs):
         self.server.start(block=False)
 
     def stop(self, force=False):
diff --git a/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/edge.py b/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/edge.py
index 354edb3bab12..32f3e582c5b0 100644
--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/edge.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/edge.py
@@ -51,7 +51,7 @@ class EdgeBrowser(Browser):
         self.webdriver_host = "localhost"
         self.webdriver_port = self.server.port
 
-    def start(self):
+    def start(self, **kwargs):
         print self.server.url
         self.server.start()
 
diff --git a/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/firefox.py b/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/firefox.py
index 7152fd7c1c20..2d45a69dbe75 100644
--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/firefox.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/firefox.py
@@ -5,6 +5,7 @@ import subprocess
 import sys
 
 import mozinfo
+import mozleak
 from mozprocess import ProcessHandler
 from mozprofile import FirefoxProfile, Preferences
 from mozprofile.permissions import ServerLocations
@@ -41,13 +42,26 @@ __wptrunner__ = {"product": "firefox",
                  "update_properties": "update_properties"}
 
 
+def get_timeout_multiplier(test_type, run_info_data, **kwargs):
+    if kwargs["timeout_multiplier"] is not None:
+        return kwargs["timeout_multiplier"]
+    if test_type == "reftest":
+        if run_info_data["debug"] or run_info_data.get("asan"):
+            return 4
+        else:
+            return 2
+    elif run_info_data["debug"] or run_info_data.get("asan"):
+        return 3
+    return 1
+
+
 def check_args(**kwargs):
     require_arg(kwargs, "binary")
     if kwargs["ssl_type"] != "none":
         require_arg(kwargs, "certutil_binary")
 
 
-def browser_kwargs(**kwargs):
+def browser_kwargs(test_type, run_info_data, **kwargs):
     return {"binary": kwargs["binary"],
             "prefs_root": kwargs["prefs_root"],
             "extra_prefs": kwargs["extra_prefs"],
@@ -58,7 +72,11 @@ def browser_kwargs(**kwargs):
             "ca_certificate_path": kwargs["ssl_env"].ca_cert_path(),
             "e10s": kwargs["gecko_e10s"],
             "stackfix_dir": kwargs["stackfix_dir"],
-            "binary_args": kwargs["binary_args"]}
+            "binary_args": kwargs["binary_args"],
+            "timeout_multiplier": get_timeout_multiplier(test_type,
+                                                         run_info_data,
+                                                         **kwargs),
+            "leak_check": kwargs["leak_check"]}
 
 
 def executor_kwargs(test_type, server_config, cache_manager, run_info_data,
@@ -66,14 +84,9 @@ def executor_kwargs(test_type, server_config, cache_manager, run_info_data,
     executor_kwargs = base_executor_kwargs(test_type, server_config,
                                            cache_manager, **kwargs)
     executor_kwargs["close_after_done"] = test_type != "reftest"
-    if kwargs["timeout_multiplier"] is None:
-        if test_type == "reftest":
-            if run_info_data["debug"] or run_info_data.get("asan"):
-                executor_kwargs["timeout_multiplier"] = 4
-            else:
-                executor_kwargs["timeout_multiplier"] = 2
-        elif run_info_data["debug"] or run_info_data.get("asan"):
-            executor_kwargs["timeout_multiplier"] = 3
+    executor_kwargs["timeout_multiplier"] = get_timeout_multiplier(test_type,
+                                                                   run_info_data,
+                                                                   **kwargs)
     if test_type == "wdspec":
         executor_kwargs["binary"] = kwargs["binary"]
         executor_kwargs["webdriver_binary"] = kwargs.get("webdriver_binary")
@@ -119,7 +132,7 @@ class FirefoxBrowser(Browser):
     def __init__(self, logger, binary, prefs_root, extra_prefs=None, debug_info=None,
                  symbols_path=None, stackwalk_binary=None, certutil_binary=None,
                  ca_certificate_path=None, e10s=False, stackfix_dir=None,
-                 binary_args=None):
+                 binary_args=None, timeout_multiplier=None, leak_check=False):
         Browser.__init__(self, logger)
         self.binary = binary
         self.prefs_root = prefs_root
@@ -140,9 +153,19 @@ class FirefoxBrowser(Browser):
         else:
             self.stack_fixer = None
 
-    def start(self):
-        self.marionette_port = get_free_port(2828, exclude=self.used_ports)
-        self.used_ports.add(self.marionette_port)
+        if timeout_multiplier:
+            self.init_timeout = self.init_timeout * timeout_multiplier
+
+        self.leak_report_file = None
+        self.leak_check = leak_check
+
+    def settings(self, test):
+        return {"check_leaks": self.leak_check and not test.leaks}
+
+    def start(self, **kwargs):
+        if self.marionette_port is None:
+            self.marionette_port = get_free_port(2828, exclude=self.used_ports)
+            self.used_ports.add(self.marionette_port)
 
         env = os.environ.copy()
         env["MOZ_DISABLE_NONLOCAL_CONNECTIONS"] = "1"
@@ -153,8 +176,7 @@ class FirefoxBrowser(Browser):
 
         self.profile = FirefoxProfile(locations=locations,
                                       preferences=preferences)
-        self.profile.set_preferences({"marionette.enabled": True,
-                                      "marionette.port": self.marionette_port,
+        self.profile.set_preferences({"marionette.port": self.marionette_port,
                                       "dom.disable_open_during_load": False,
                                       "network.dns.localDomains": ",".join(hostnames),
                                       "network.proxy.type": 0,
@@ -162,6 +184,14 @@ class FirefoxBrowser(Browser):
         if self.e10s:
             self.profile.set_preferences({"browser.tabs.remote.autostart": True})
 
+        if self.leak_check and kwargs.get("check_leaks", True):
+            self.leak_report_file = os.path.join(self.profile.profile, "runtests_leaks.log")
+            if os.path.exists(self.leak_report_file):
+                os.remove(self.leak_report_file)
+            env["XPCOM_MEM_BLOAT_LOG"] = self.leak_report_file
+        else:
+            self.leak_report_file = None
+
         # Bug 1262954: winxp + e10s, disable hwaccel
         if (self.e10s and platform.system() in ("Windows", "Microsoft") and
             '5.1' in platform.version()):
@@ -217,6 +247,24 @@ class FirefoxBrowser(Browser):
             except OSError:
                 # This can happen on Windows if the process is already dead
                 pass
+        self.logger.debug("stopped")
+
+    def process_leaks(self):
+        self.logger.debug("PROCESS LEAKS %s" % self.leak_report_file)
+        if self.leak_report_file is None:
+            return
+        mozleak.process_leak_log(
+            self.leak_report_file,
+            leak_thresholds={
+                "default": 0,
+                "tab": 10000,  # See dependencies of bug 1051230.
+                # GMP rarely gets a log, but when it does, it leaks a little.
+                "geckomediaplugin": 20000,
+            },
+            ignore_missing_leaks=["geckomediaplugin"],
+            log=self.logger,
+            stack_fixer=self.stack_fixer
+        )
 
     def pid(self):
         if self.runner.process_handler is None:
@@ -243,6 +291,7 @@ class FirefoxBrowser(Browser):
 
     def cleanup(self):
         self.stop()
+        self.process_leaks()
 
     def executor_browser(self):
         assert self.marionette_port is not None
diff --git a/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/sauce.py b/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/sauce.py
index 7300b6afefb8..a2f29a4c54f3 100644
--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/sauce.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/sauce.py
@@ -92,7 +92,7 @@ def check_args(**kwargs):
     require_arg(kwargs, "sauce_key")
 
 
-def browser_kwargs(**kwargs):
+def browser_kwargs(test_type, run_info_data, **kwargs):
     sauce_config = get_sauce_config(**kwargs)
 
     return {"sauce_config": sauce_config}
diff --git a/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/servo.py b/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/servo.py
index e24e4dfd9dfe..89d69ab9e543 100644
--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/servo.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/servo.py
@@ -27,7 +27,7 @@ def check_args(**kwargs):
     require_arg(kwargs, "binary")
 
 
-def browser_kwargs(**kwargs):
+def browser_kwargs(test_type, run_info_data, **kwargs):
     return {
         "binary": kwargs["binary"],
         "debug_info": kwargs["debug_info"],
diff --git a/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/servodriver.py b/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/servodriver.py
index 9575e0fbff9d..c251de84d163 100644
--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/servodriver.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/servodriver.py
@@ -39,7 +39,7 @@ def check_args(**kwargs):
     require_arg(kwargs, "binary")
 
 
-def browser_kwargs(**kwargs):
+def browser_kwargs(test_type, run_info_data, **kwargs):
     return {
         "binary": kwargs["binary"],
         "debug_info": kwargs["debug_info"],
@@ -91,7 +91,7 @@ class ServoWebDriverBrowser(Browser):
         self.command = None
         self.user_stylesheets = user_stylesheets if user_stylesheets else []
 
-    def start(self):
+    def start(self, **kwargs):
         self.webdriver_port = get_free_port(4444, exclude=self.used_ports)
         self.used_ports.add(self.webdriver_port)
 
diff --git a/testing/web-platform/tests/tools/wptrunner/wptrunner/executors/executormarionette.py b/testing/web-platform/tests/tools/wptrunner/wptrunner/executors/executormarionette.py
index 21e6509af167..51b9f30f470f 100644
--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/executors/executormarionette.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/executors/executormarionette.py
@@ -48,12 +48,13 @@ def do_delayed_imports():
 
 
 class MarionetteProtocol(Protocol):
-    def __init__(self, executor, browser):
+    def __init__(self, executor, browser, timeout_multiplier=1):
         do_delayed_imports()
 
         Protocol.__init__(self, executor, browser)
         self.marionette = None
         self.marionette_port = browser.marionette_port
+        self.timeout_multiplier = timeout_multiplier
         self.timeout = None
         self.runner_handle = None
 
@@ -62,14 +63,16 @@ class MarionetteProtocol(Protocol):
         Protocol.setup(self, runner)
 
         self.logger.debug("Connecting to Marionette on port %i" % self.marionette_port)
+        startup_timeout = marionette.Marionette.DEFAULT_STARTUP_TIMEOUT * self.timeout_multiplier
         self.marionette = marionette.Marionette(host='localhost',
                                                 port=self.marionette_port,
-                                                socket_timeout=None)
+                                                socket_timeout=None,
+                                                startup_timeout=startup_timeout)
 
         # XXX Move this timeout somewhere
         self.logger.debug("Waiting for Marionette connection")
         while True:
-            success = self.marionette.wait_for_port(60)
+            success = self.marionette.wait_for_port(60 * self.timeout_multiplier)
             #When running in a debugger wait indefinitely for firefox to start
             if success or self.executor.debug_info is None:
                 break
@@ -407,7 +410,7 @@ class MarionetteTestharnessExecutor(TestharnessExecutor):
                                      timeout_multiplier=timeout_multiplier,
                                      debug_info=debug_info)
 
-        self.protocol = MarionetteProtocol(self, browser)
+        self.protocol = MarionetteProtocol(self, browser, timeout_multiplier)
         self.script = open(os.path.join(here, "testharness_marionette.js")).read()
         self.close_after_done = close_after_done
         self.window_id = str(uuid.uuid4())
diff --git a/testing/web-platform/tests/tools/wptrunner/wptrunner/manifestexpected.py b/testing/web-platform/tests/tools/wptrunner/wptrunner/manifestexpected.py
index fb5c1b1e7239..5d57b70e517c 100644
--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/manifestexpected.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/manifestexpected.py
@@ -111,6 +111,10 @@ class ExpectedManifest(ManifestItem):
     def restart_after(self):
         return bool_prop("restart-after", self)
 
+    @property
+    def leaks(self):
+        return bool_prop("leaks", self)
+
     @property
     def tags(self):
         return tags(self)
@@ -129,6 +133,10 @@ class DirectoryManifest(ManifestItem):
     def restart_after(self):
         return bool_prop("restart-after", self)
 
+    @property
+    def leaks(self):
+        return bool_prop("leaks", self)
+
     @property
     def tags(self):
         return tags(self)
@@ -174,6 +182,10 @@ class TestNode(ManifestItem):
     def restart_after(self):
         return bool_prop("restart-after", self)
 
+    @property
+    def leaks(self):
+        return bool_prop("leaks", self)
+
     @property
     def tags(self):
         return tags(self)
diff --git a/testing/web-platform/tests/tools/wptrunner/wptrunner/testloader.py b/testing/web-platform/tests/tools/wptrunner/wptrunner/testloader.py
index 74dce4aafe33..2b2033f3d213 100644
--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/testloader.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/testloader.py
@@ -92,8 +92,8 @@ class EqualTimeChunker(TestChunker):
                 by_dir[test_dir] = PathData(test_dir)
 
             data = by_dir[test_dir]
-            time = sum(wpttest.DEFAULT_TIMEOUT if test.timeout !=
-                       "long" else wpttest.LONG_TIMEOUT for test in tests)
+            time = sum(test.default_timeout if test.timeout !=
+                       "long" else test.long_timeout for test in tests)
             data.time += time
             total_time += time
             data.tests.append((test_type, test_path, tests))
@@ -627,7 +627,6 @@ class PathGroupedSource(TestSource):
                     self.current_queue.put(item)
             except Empty:
                 return None
-
         return self.current_queue
 
     def requeue_test(self, test):
diff --git a/testing/web-platform/tests/tools/wptrunner/wptrunner/testrunner.py b/testing/web-platform/tests/tools/wptrunner/wptrunner/testrunner.py
index e422cfefec61..d494010a9f76 100644
--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/testrunner.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/testrunner.py
@@ -153,11 +153,20 @@ class BrowserManager(object):
         self.logger = logger
         self.browser = browser
         self.no_timeout = no_timeout
+        self.browser_settings = None
 
         self.started = False
 
         self.init_timer = None
 
+    def update_settings(self, test):
+        browser_settings = self.browser.settings(test)
+        restart_required = ((self.browser_settings is not None and
+                             self.browser_settings != browser_settings) or
+                            test.expected() == "CRASH")
+        self.browser_settings = browser_settings
+        return restart_required
+
     def init(self):
         """Launch the browser that is being tested,
         and the TestRunner process that will run the tests."""
@@ -178,7 +187,8 @@ class BrowserManager(object):
             try:
                 if self.init_timer is not None:
                     self.init_timer.start()
-                self.browser.start()
+                self.logger.debug("Starting browser with settings %r" % self.browser_settings)
+                self.browser.start(**self.browser_settings)
                 self.browser_pid = self.browser.pid()
             except:
                 self.logger.warning("Failure during init %s" % traceback.format_exc())
@@ -437,6 +447,8 @@ class TestRunnerManager(threading.Thread):
             self.logger.error("Max restarts exceeded")
             return RunnerManagerState.error()
 
+        self.browser.update_settings(self.state.test)
+
         result = self.browser.init()
         if result is Stop:
             return RunnerManagerState.error()
@@ -495,15 +507,21 @@ class TestRunnerManager(threading.Thread):
                     return None, None
             try:
                 # Need to block here just to allow for contention with other processes
-                test = test_queue.get(block=True, timeout=1)
+                test = test_queue.get(block=True, timeout=2)
             except Empty:
-                pass
+                if test_queue.empty():
+                    test_queue = None
         return test, test_queue
 
     def run_test(self):
         assert isinstance(self.state, RunnerManagerState.running)
         assert self.state.test is not None
 
+        if self.browser.update_settings(self.state.test):
+            self.logger.info("Restarting browser for new test environment")
+            return RunnerManagerState.restarting(self.state.test,
+                                                 self.state.test_queue)
+
         self.logger.test_start(self.state.test.id)
         self.send_message("run_test", self.state.test)
 
diff --git a/testing/web-platform/tests/tools/wptrunner/wptrunner/tests/test_chunker.py b/testing/web-platform/tests/tools/wptrunner/wptrunner/tests/test_chunker.py
index 4968940feb8b..062b687fab9a 100644
--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/tests/test_chunker.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/tests/test_chunker.py
@@ -12,6 +12,8 @@ from wptrunner.testloader import EqualTimeChunker
 structured.set_default_logger(structured.structuredlog.StructuredLogger("TestChunker"))
 
 class MockTest(object):
+    default_timeout = 10
+
     def __init__(self, id, timeout=10):
         self.id = id
         self.item_type = "testharness"
diff --git a/testing/web-platform/tests/tools/wptrunner/wptrunner/update/sync.py b/testing/web-platform/tests/tools/wptrunner/wptrunner/update/sync.py
index 3f6092a046a0..fb7948874c48 100644
--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/update/sync.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/update/sync.py
@@ -1,4 +1,6 @@
+import fnmatch
 import os
+import re
 import shutil
 import sys
 import uuid
@@ -42,7 +44,7 @@ POSSIBILITY OF SUCH DAMAGE.
 """
 
 
-def copy_wpt_tree(tree, dest):
+def copy_wpt_tree(tree, dest, excludes=None, includes=None):
     """Copy the working copy of a Tree to a destination directory.
 
     :param tree: The Tree to copy.
@@ -51,9 +53,24 @@ def copy_wpt_tree(tree, dest):
         assert os.path.isdir(dest)
 
     shutil.rmtree(dest)
+
     os.mkdir(dest)
 
+    if excludes is None:
+        excludes = []
+
+    excludes = [re.compile(fnmatch.translate(item)) for item in excludes]
+
+    if includes is None:
+        includes = []
+
+    includes = [re.compile(fnmatch.translate(item)) for item in includes]
+
     for tree_path in tree.paths():
+        if (any(item.match(tree_path) for item in excludes) and
+            not any(item.match(tree_path) for item in includes)):
+            continue
+
         source_path = os.path.join(tree.root, tree_path)
         dest_path = os.path.join(dest, tree_path)
 
@@ -79,6 +96,7 @@ def add_license(dest):
     with open(os.path.join(dest, "LICENSE"), "w") as f:
         f.write(bsd_license)
 
+
 class UpdateCheckout(Step):
     """Pull changes from upstream into the local sync tree."""
 
@@ -142,7 +160,9 @@ class CopyWorkTree(Step):
 
     def create(self, state):
         copy_wpt_tree(state.sync_tree,
-                      state.tests_path)
+                      state.tests_path,
+                      excludes=state.path_excludes,
+                      includes=state.path_includes)
 
 
 class CreateSyncPatch(Step):
diff --git a/testing/web-platform/tests/tools/wptrunner/wptrunner/update/tree.py b/testing/web-platform/tests/tools/wptrunner/wptrunner/update/tree.py
index a15df907aa41..01df0b4f94a3 100644
--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/update/tree.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/update/tree.py
@@ -312,9 +312,8 @@ class GitTree(object):
 
         for repo_path in repo_paths:
             paths = vcs.git("ls-tree", "-r", "--name-only", "HEAD", repo=repo_path).split("\n")
-            rel_path = os.path.relpath(repo_path, self.root)
-            rv.extend(os.path.join(rel_path, item.strip()) for item in paths if item.strip())
-
+            rv.extend(os.path.relpath(os.path.join(repo_path, item), self.root) for item in paths
+                      if item.strip())
         return rv
 
     def submodules(self):
diff --git a/testing/web-platform/tests/tools/wptrunner/wptrunner/update/update.py b/testing/web-platform/tests/tools/wptrunner/wptrunner/update/update.py
index 4a5e7ab73d4b..4c0099e63bb1 100644
--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/update/update.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/update/update.py
@@ -73,6 +73,8 @@ class SyncFromUpstream(Step):
             state.target_rev = kwargs["rev"]
             state.no_patch = kwargs["no_patch"]
             state.suite_name = kwargs["suite_name"]
+            state.path_excludes = kwargs["exclude"]
+            state.path_includes = kwargs["include"]
             runner = SyncFromUpstreamRunner(self.logger, state)
             runner.run()
 
diff --git a/testing/web-platform/tests/tools/wptrunner/wptrunner/wptcommandline.py b/testing/web-platform/tests/tools/wptrunner/wptrunner/wptcommandline.py
index 01d3ab9fb52c..5d44df2fad9b 100644
--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/wptcommandline.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/wptcommandline.py
@@ -177,6 +177,8 @@ scheme host and port.""")
     gecko_group.add_argument("--setpref", dest="extra_prefs", action='append',
                              default=[], metavar="PREF=VALUE",
                              help="Defines an extra user preference (overrides those in prefs_root)")
+    gecko_group.add_argument("--leak-check", dest="leak_check", action="store_true",
+                             help="Enable leak checking")
 
     servo_group = parser.add_argument_group("Servo-specific")
     servo_group.add_argument("--user-stylesheet",
@@ -424,6 +426,10 @@ def create_parser_update(product_choices=None):
     parser.add_argument("--ignore-existing", action="store_true", help="When updating test results only consider results from the logfiles provided, not existing expectations.")
     parser.add_argument("--continue", action="store_true", help="Continue a previously started run of the update script")
     parser.add_argument("--abort", action="store_true", help="Clear state from a previous incomplete run of the update script")
+    parser.add_argument("--exclude", action="store", nargs="*",
+                        help="List of glob-style paths to exclude when syncing tests")
+    parser.add_argument("--include", action="store", nargs="*",
+                        help="List of glob-style paths to include which would otherwise be excluded when syncing tests")
     # Should make this required iff run=logfile
     parser.add_argument("run_log", nargs="*", type=abs_path,
                         help="Log file from run of tests")
diff --git a/testing/web-platform/tests/tools/wptrunner/wptrunner/wptrunner.py b/testing/web-platform/tests/tools/wptrunner/wptrunner/wptrunner.py
index bf9b74e4398f..65e5d7f7e0c1 100644
--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/wptrunner.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/wptrunner.py
@@ -158,8 +158,6 @@ def run_tests(config, test_paths, product, **kwargs):
                 logger.critical("Error starting test environment: %s" % e.message)
                 raise
 
-            browser_kwargs = get_browser_kwargs(ssl_env=ssl_env, **kwargs)
-
             repeat = kwargs["repeat"]
             repeat_count = 0
             repeat_until_unexpected = kwargs["repeat_until_unexpected"]
@@ -186,9 +184,11 @@ def run_tests(config, test_paths, product, **kwargs):
                     else:
                         browser_cls = target_browser_cls
 
-                    for test in test_loader.disabled_tests[test_type]:
-                        logger.test_start(test.id)
-                        logger.test_end(test.id, status="SKIP")
+                    browser_kwargs = get_browser_kwargs(test_type,
+                                                        run_info,
+                                                        ssl_env=ssl_env,
+                                                        **kwargs)
+
 
                     executor_cls = executor_classes.get(test_type)
                     executor_kwargs = get_executor_kwargs(test_type,
@@ -202,6 +202,9 @@ def run_tests(config, test_paths, product, **kwargs):
                                      (test_type, product))
                         continue
 
+                    for test in test_loader.disabled_tests[test_type]:
+                        logger.test_start(test.id)
+                        logger.test_end(test.id, status="SKIP")
 
                     with ManagerGroup("web-platform-tests",
                                       kwargs["processes"],
diff --git a/testing/web-platform/tests/tools/wptrunner/wptrunner/wpttest.py b/testing/web-platform/tests/tools/wptrunner/wptrunner/wpttest.py
index d144cd66ea78..12701f611179 100644
--- a/testing/web-platform/tests/tools/wptrunner/wptrunner/wpttest.py
+++ b/testing/web-platform/tests/tools/wptrunner/wptrunner/wpttest.py
@@ -1,6 +1,3 @@
-DEFAULT_TIMEOUT = 10  # seconds
-LONG_TIMEOUT = 60  # seconds
-
 import os
 
 import mozinfo
@@ -95,17 +92,21 @@ class RunInfo(dict):
 
 
 class Test(object):
+
     result_cls = None
     subtest_result_cls = None
     test_type = None
 
+    default_timeout = 10  # seconds
+    long_timeout = 60  # seconds
+
     def __init__(self, tests_root, url, inherit_metadata, test_metadata,
-                 timeout=DEFAULT_TIMEOUT, path=None, protocol="http"):
+                 timeout=None, path=None, protocol="http"):
         self.tests_root = tests_root
         self.url = url
         self._inherit_metadata = inherit_metadata
         self._test_metadata = test_metadata
-        self.timeout = timeout
+        self.timeout = timeout if timeout is not None else self.default_timeout
         self.path = path
         self.environment = {"protocol": protocol, "prefs": self.prefs}
 
@@ -114,7 +115,7 @@ class Test(object):
 
     @classmethod
     def from_manifest(cls, manifest_item, inherit_metadata, test_metadata):
-        timeout = LONG_TIMEOUT if manifest_item.timeout == "long" else DEFAULT_TIMEOUT
+        timeout = cls.long_timeout if manifest_item.timeout == "long" else cls.default_timeout
         protocol = "https" if hasattr(manifest_item, "https") and manifest_item.https else "http"
         return cls(manifest_item.source_file.tests_root,
                    manifest_item.url,
@@ -168,6 +169,14 @@ class Test(object):
                 return True
         return False
 
+    @property
+    def leaks(self):
+        for meta in self.itermeta(None):
+            leaks = meta.leaks
+            if leaks is not None:
+                return leaks
+        return False
+
     @property
     def tags(self):
         tags = set()
@@ -237,8 +246,7 @@ class ReftestTest(Test):
     test_type = "reftest"
 
     def __init__(self, tests_root, url, inherit_metadata, test_metadata, references,
-                 timeout=DEFAULT_TIMEOUT, path=None, viewport_size=None,
-                 dpi=None, protocol="http"):
+                 timeout=None, path=None, viewport_size=None, dpi=None, protocol="http"):
         Test.__init__(self, tests_root, url, inherit_metadata, test_metadata, timeout,
                       path, protocol)
 
@@ -258,7 +266,7 @@ class ReftestTest(Test):
                       nodes=None,
                       references_seen=None):
 
-        timeout = LONG_TIMEOUT if manifest_test.timeout == "long" else DEFAULT_TIMEOUT
+        timeout = cls.long_timeout if manifest_test.timeout == "long" else cls.default_timeout
 
         if nodes is None:
             nodes = {}
@@ -322,10 +330,14 @@ class ReftestTest(Test):
 
 
 class WdspecTest(Test):
+
     result_cls = WdspecResult
     subtest_result_cls = WdspecSubtestResult
     test_type = "wdspec"
 
+    default_timeout = 25
+    long_timeout = 120
+
 
 manifest_test_cls = {"reftest": ReftestTest,
                      "testharness": TestharnessTest,