Simplify Chrome Android setup

Automatically start adb, connect to device, and set up port forwarding.
The list of ports to be forwarded is read from server config at run
time. When a test run is completed, port forwarding is torn down.

Also fix testrunner so that setup & cleanup balance out (called at enter
& exit of a Browser context, respectively). Previously, cleaup() didn't
do anything in all browsers, so the issue wasn't discovered. In this
commit, cleanup() is used for uninstalling port forwarding.

Document for Chrome Android is adjusted accordingly.

docs/_running-tests/chrome_android.md

@@ -1,6 +1,10 @@
 To run WPT on Chrome on an android device, some additional set up is required.
-First until we find a better way, we need to root the android device and update
-the /etc/hosts file to include
+
+First of all, as usual Android development, we need to have `adb` and be able to
+connect to the device.
+
+Furthermore, until we find a better way, we need to root the android device and
+update the /etc/hosts file to include
 
 ```
 127.0.0.1   web-platform.test
@@ -12,22 +16,6 @@ the /etc/hosts file to include
 0.0.0.0     nonexistent-origin.web-platform.test
 ```
 
-Next, we need to start adb and reverse forward the web-platform.tests ports
-
-```
-adb start-server
-```
-
-Add any ports that you need based on your config. For example:
-```
-adb reverse tcp:8000 tcp:8000
-adb reverse tcp:8001 tcp:8001
-adb reverse tcp:8081 tcp:8081
-adb reverse tcp:8444 tcp:8444
-adb reverse tcp:9001 tcp:9001
-adb reverse tcp:9444 tcp:9444
-```
-
 After this, we may run wpt with the `chrome_android` product
 
 ```

tools/wpt/browser.py

@@ -281,6 +281,7 @@ def prepare_environment(self):
                 logger.critical("dbus not running and can't be started")
                 sys.exit(1)
 
+
 class ChromeAndroid(Browser):
     """Chrome-specific interface for android.
 
@@ -293,49 +294,16 @@ class ChromeAndroid(Browser):
     def install(self, dest=None):
         raise NotImplementedError
 
-    def platform_string(self):
-        raise NotImplementedError
-
     def find_webdriver(self):
         return find_executable("chromedriver")
 
     def install_webdriver(self, dest=None):
-        """Install latest Webdriver."""
-        if dest is None:
-            dest = os.pwd
-        latest = get("http://chromedriver.storage.googleapis.com/LATEST_RELEASE").text.strip()
-        url = "http://chromedriver.storage.googleapis.com/%s/chromedriver_%s.zip" % (latest,
-                                                                                     self.platform_string())
-        unzip(get(url).raw, dest)
-
-        path = find_executable("chromedriver", dest)
-        st = os.stat(path)
-        os.chmod(path, st.st_mode | stat.S_IEXEC)
-        return path
+        chrome = Chrome()
+        return chrome.install_webdriver(dest)
 
     def version(self, root):
         raise NotImplementedError
 
-    def prepare_environment(self):
-        # https://bugs.chromium.org/p/chromium/issues/detail?id=713947
-        logger.debug("DBUS_SESSION_BUS_ADDRESS %s" % os.environ.get("DBUS_SESSION_BUS_ADDRESS"))
-        if "DBUS_SESSION_BUS_ADDRESS" not in os.environ:
-            if find_executable("dbus-launch"):
-                logger.debug("Attempting to start dbus")
-                dbus_conf = subprocess.check_output(["dbus-launch"])
-                logger.debug(dbus_conf)
-
-                # From dbus-launch(1):
-                #
-                # > When dbus-launch prints bus information to standard output,
-                # > by default it is in a simple key-value pairs format.
-                for line in dbus_conf.strip().split("\n"):
-                    key, _, value = line.partition("=")
-                    os.environ[key] = value
-            else:
-                logger.critical("dbus not running and can't be started")
-                sys.exit(1)
-
 
 class Opera(Browser):
     """Opera-specific interface.

tools/wptrunner/wptrunner/browsers/chrome_android.py

@@ -1,3 +1,6 @@
+import subprocess
+
+from ..config import *
 from .base import Browser, ExecutorBrowser, require_arg
 from ..webdriver_server import ChromeDriverServer
 from ..executors import executor_kwargs as base_executor_kwargs
@@ -17,6 +20,8 @@
                  "env_extras": "env_extras",
                  "env_options": "env_options"}
 
+__wptserve_ports = []
+
 
 def check_args(**kwargs):
     require_arg(kwargs, "webdriver_binary")
@@ -32,6 +37,10 @@ def executor_kwargs(test_type, server_config, cache_manager, run_info_data,
                     **kwargs):
     from selenium.webdriver import DesiredCapabilities
 
+    # Use extend() to modify the global list in place.
+    __wptserve_ports.extend(server_config['http'] + server_config['https'] +
+                            server_config['ws'] + server_config['wss'])
+
     executor_kwargs = base_executor_kwargs(test_type, server_config,
                                            cache_manager, **kwargs)
     executor_kwargs["close_after_done"] = True
@@ -76,6 +85,17 @@ def __init__(self, logger, binary, webdriver_binary="chromedriver",
                                          binary=webdriver_binary,
                                          args=webdriver_args)
 
+    def _adb_run(self, args):
+        self.logger.info('adb ' + ' '.join(args))
+        subprocess.check_call(['adb'] + args)
+
+    def setup(self):
+        self._adb_run(['wait-for-device'])
+        self._adb_run(['forward', '--remove-all'])
+        self._adb_run(['reverse', '--remove-all'])
+        for port in __wptserve_ports:
+            self._adb_run(['reverse', 'tcp:%d' % port, 'tcp:%d' % port])
+
     def start(self, **kwargs):
         self.server.start(block=False)
 
@@ -93,6 +113,8 @@ def is_alive(self):
 
     def cleanup(self):
         self.stop()
+        self._adb_run(['forward', '--remove-all'])
+        self._adb_run(['reverse', '--remove-all'])
 
     def executor_browser(self):
         return ExecutorBrowser, {"webdriver_url": self.server.url}

tools/wptrunner/wptrunner/testrunner.py

@@ -229,7 +229,6 @@ def stop(self, force=False):
     def cleanup(self):
         if self.init_timer is not None:
             self.init_timer.cancel()
-        self.browser.cleanup()
 
     def check_for_crashes(self):
         self.browser.check_for_crashes()