Merge pull request #101 from w3c/jgraham/chrome_args_check

Fix Chrome support so that --webdriver-binary is required and --binary is optional

wptrunner/browsers/chrome.py

@@ -20,7 +20,7 @@
 
 
 def check_args(**kwargs):
-    require_arg(kwargs, "binary")
+    require_arg(kwargs, "webdriver_binary")
 
 
 def browser_kwargs(**kwargs):
@@ -35,9 +35,9 @@ 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"] = True
-    executor_kwargs["capabilities"] = dict(DesiredCapabilities.CHROME.items() +
-                                           {"chromeOptions":
-                                            {"binary": kwargs["binary"]}}.items())
+    executor_kwargs["capabilities"] = dict(DesiredCapabilities.CHROME.items())
+    if kwargs["binary"] is not None:
+        executor_kwargs["capabilities"]["chromeOptions"] = {"binary": kwargs["binary"]}
 
     return executor_kwargs