Use selenium to drive gecko test

etc/ci/performance/gecko_driver.py

@@ -0,0 +1,78 @@
+#!/usr/bin/env python3
+
+# 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 selenium import webdriver
+from selenium.common.exceptions import TimeoutException
+
+
+def execute_gecko_test(testcase, timeout):
+    firefox_binary = "./firefox/firefox/firefox"
+    driver = webdriver.Firefox(firefox_binary=firefox_binary)
+    driver.set_page_load_timeout(timeout)
+    failed = False
+    try:
+        driver.get(testcase)
+    except TimeoutException:
+        print("Timeout!")
+        driver.quit()
+        failed = True
+
+    timings = {
+        "testcase": testcase,
+        "title": driver.title.replace(",", ",")
+    }
+
+    timing_names = [
+        "navigationStart",
+        "unloadEventStart",
+        "domLoading",
+        "fetchStart",
+        "responseStart",
+        "loadEventEnd",
+        "connectStart",
+        "domainLookupStart",
+        "redirectStart",
+        "domContentLoadedEventEnd",
+        "requestStart",
+        "secureConnectionStart",
+        "connectEnd",
+        "loadEventStart",
+        "domInteractive",
+        "domContentLoadedEventStart",
+        "redirectEnd",
+        "domainLookupEnd",
+        "unloadEventEnd",
+        "responseEnd",
+        "domComplete",
+    ]
+
+    # We could have just run
+    #     timings = driver.execute_script("return performance.timing")
+    # But for some test case the webdriver will fail with "too much recursion"
+    # So we need to get the timing fields one by one
+    for name in timing_names:
+        if failed:
+            if name == "navigationStart":
+                timings[name] = 0
+            else:
+                timings[name] = -1
+        else:
+            timings[name] = driver.execute_script(
+                "return performance.timing.{0}".format(name)
+            )
+
+    timings['testcase'] = testcase
+    # driver.quit() gives an "'NoneType' object has no attribute 'path'" error.
+    # Fixed in
+    # https://github.com/SeleniumHQ/selenium/commit/9157c7071f9900c2608f5ca40ae4f518ed373b96
+    driver.quit()
+    return [timings]
+
+if __name__ == '__main__':
+    # Just for manual testing
+    from pprint import pprint
+    url = "http://localhost:8000/page_load_test/tp5n/dailymail.co.uk/www.dailymail.co.uk/ushome/index.html"
+    pprint(execute_gecko_test(url, 15))