[wpt] Support detecting Chrome for Android version

Consequently, we can now install the correct ChromeDriver version.

* The change also includes some drive-by whitespace fixes in the file.

Author: Hexcles

docs/running-tests/chrome_android.md

@@ -7,9 +7,9 @@ connect to the device. Run `adb devices` to verify.
 
 Currently, Android support is a prototype with some known issues:
 
-* We install ChromeDriver corresponding to the Chrome version on your *host*,
-  so you will need a special flag to bypass ChromeDriver's version check if the
-  test device runs a different version of Chrome from your host.
+* If you have previously run `./wpt run` against Chrome, you might need to
+  remove `_venv/bin/chromedriver` so that we can install the correct
+  ChromeDriver corresponding to your Chrome for Android version.
 * The package name is hard coded. If you are testing a custom build, you will
   need to search and replace `com.android.chrome` in `tools/`.
 * We do not support reftests at the moment.
@@ -19,5 +19,5 @@ Note: rooting the device or installing a root CA is no longer required.
 Example:
 
 ```bash
-./wpt run --webdriver-arg=--disable-build-check --test-type=testharness chrome_android TESTS
+./wpt run --test-type=testharness chrome_android TESTS
 ```

tools/wpt/browser.py

@@ -36,6 +36,7 @@ def handle_remove_readonly(func, path, exc):
     else:
         raise
 
+
 class Browser(object):
     __metaclass__ = ABCMeta
 
@@ -534,28 +535,32 @@ def _chromium_chromedriver_url(self, chrome_version):
                 self.chromium_platform_string(), revision, self.platform_string())
         return url
 
-    def _latest_chromedriver_url(self, browser_binary=None):
-        chrome_version = self.version(browser_binary)
-        assert chrome_version, "Cannot detect the version of Chrome"
+    def _latest_chromedriver_url(self, chrome_version):
         # Remove channel suffixes (e.g. " dev").
         chrome_version = chrome_version.split(' ')[0]
         return (self._official_chromedriver_url(chrome_version) or
                 self._chromium_chromedriver_url(chrome_version))
 
-    def install_webdriver(self, dest=None, channel=None, browser_binary=None):
+    def install_webdriver_by_version(self, version, dest=None):
+        assert version, "Cannot install ChromeDriver without Chrome version"
         if dest is None:
             dest = os.pwd
-        if browser_binary is None:
-            browser_binary = self.find_binary(channel)
-        url = self._latest_chromedriver_url(browser_binary)
+        url = self._latest_chromedriver_url(version)
         self.logger.info("Downloading ChromeDriver from %s" % url)
         unzip(get(url).raw, dest)
-        chromedriver_dir = os.path.join(dest, 'chromedriver_%s' % self.platform_string())
+        chromedriver_dir = os.path.join(
+            dest, 'chromedriver_%s' % self.platform_string())
         if os.path.isfile(os.path.join(chromedriver_dir, "chromedriver")):
             shutil.move(os.path.join(chromedriver_dir, "chromedriver"), dest)
             shutil.rmtree(chromedriver_dir)
         return find_executable("chromedriver", dest)
 
+    def install_webdriver(self, dest=None, channel=None, browser_binary=None):
+        if browser_binary is None:
+            browser_binary = self.find_binary(channel)
+        return self.install_webdriver_by_version(
+            self.version(browser_binary), dest)
+
     def version(self, binary=None, webdriver_binary=None):
         if not binary:
             self.logger.warning("No browser binary provided.")
@@ -585,6 +590,9 @@ class ChromeAndroid(Browser):
     product = "chrome_android"
     requirements = "requirements_chrome_android.txt"
 
+    def __init__(self, logger):
+        super(ChromeAndroid, self).__init__(logger)
+
     def install(self, dest=None, channel=None):
         raise NotImplementedError
 
@@ -596,10 +604,20 @@ def find_webdriver(self, channel=None):
 
     def install_webdriver(self, dest=None, channel=None, browser_binary=None):
         chrome = Chrome(self.logger)
-        return chrome.install_webdriver(dest, channel)
+        return chrome.install_webdriver_by_version(self.version(), dest)
 
     def version(self, binary=None, webdriver_binary=None):
-        return None
+        command = ['adb', 'shell', 'dumpsys', 'package', 'com.android.chrome']
+        try:
+            output = call(*command)
+        except (subprocess.CalledProcessError, OSError):
+            self.logger.warning("Failed to call %s" % " ".join(command))
+            return None
+        match = re.search(r'versionName=(.*)', output)
+        if not match:
+            self.logger.warning("Failed to find versionName")
+            return None
+        return match.group(1)
 
 
 class ChromeiOS(Browser):
@@ -699,6 +717,7 @@ def version(self, binary=None, webdriver_binary=None):
         if m:
             return m.group(0)
 
+
 class EdgeChromium(Browser):
     """MicrosoftEdge-specific interface."""
     platform = {
@@ -725,16 +744,16 @@ def find_binary(self, venv_path=None, channel=None):
                             os.path.expandvars("$SYSTEMDRIVE\\Program Files\\Microsoft\\Edge Dev\\Application"),
                             os.path.expandvars("$SYSTEMDRIVE\\Program Files (x86)\\Microsoft\\Edge Beta\\Application"),
                             os.path.expandvars("$SYSTEMDRIVE\\Program Files (x86)\\Microsoft\\Edge Dev\\Application"),
-                            os.path.expanduser("~\\AppData\Local\\Microsoft\\Edge SxS\\Application"),]
+                            os.path.expanduser("~\\AppData\Local\\Microsoft\\Edge SxS\\Application")]
                 return find_executable(binaryname, os.pathsep.join(winpaths))
         if self.platform == "macos":
             binaryname = "Microsoft Edge Canary"
             binary = find_executable(binaryname)
             if not binary:
                 macpaths = ["/Applications/Microsoft Edge.app/Contents/MacOS",
-                    os.path.expanduser("~/Applications/Microsoft Edge.app/Contents/MacOS"),
-                    "/Applications/Microsoft Edge Canary.app/Contents/MacOS",
-                    os.path.expanduser("~/Applications/Microsoft Edge Canary.app/Contents/MacOS")]
+                            os.path.expanduser("~/Applications/Microsoft Edge.app/Contents/MacOS"),
+                            "/Applications/Microsoft Edge Canary.app/Contents/MacOS",
+                            os.path.expanduser("~/Applications/Microsoft Edge Canary.app/Contents/MacOS")]
                 return find_executable("Microsoft Edge Canary", os.pathsep.join(macpaths))
         return binary
 
@@ -797,6 +816,7 @@ def version(self, binary=None, webdriver_binary=None):
             self.logger.warning("Failed to find Edge binary.")
             return None
 
+
 class Edge(Browser):
     """Edge-specific interface."""
 

tools/wpt/install.py

@@ -6,6 +6,7 @@
 latest_channels = {
     'firefox': 'nightly',
     'chrome': 'dev',
+    'chrome_android': 'dev',
     'edgechromium': 'dev',
     'safari': 'preview',
     'servo': 'nightly'