Add support for codepen to form_based_credentials_background

tools/telemetry/telemetry/core/backends/form_based_credentials_backend.py

Index: tools/telemetry/telemetry/core/backends/form_based_credentials_backend.py
diff --git a/tools/telemetry/telemetry/core/backends/form_based_credentials_backend.py b/tools/telemetry/telemetry/core/backends/form_based_credentials_backend.py
index bb32f32251a3489a3053af0629642ad7fd8b00a9..cf3c9fdcbf3139873f83271f545159f6b09afa64 100644
--- a/tools/telemetry/telemetry/core/backends/form_based_credentials_backend.py
+++ b/tools/telemetry/telemetry/core/backends/form_based_credentials_backend.py
@@ -15,9 +15,14 @@ def _WaitForLoginFormToLoad(backend, login_form_id, tab):
   # Wait until the form is submitted and the page completes loading.
   util.WaitFor(IsFormLoadedOrAlreadyLoggedIn, 60)
 
-def _SubmitFormAndWait(form_id, tab):
-  tab.ExecuteJavaScript(
-      'document.getElementById("%s").submit();' % form_id)
+def _SubmitFormAndWait(form_id, button_id, tab):
+  if button_id:
+    tab.ExecuteJavaScript('setTimeout(function() {'
+                          '  document.getElementById("%s").click();'
+                          '}, 1000);' % button_id)

[tonyg, 2014/08/20 17:37:17]

Is the timeout necessary in addition to the submit() vs. click() change? Or
would just click() work?

[sullivan, 2014/08/21 21:55:23]

Yes, it's necessary. I get an error message with an immediate click() :/

+  else:
+    tab.ExecuteJavaScript(
+        'document.getElementById("%s").submit();' % form_id)
 
   def FinishedLoading():
     return not tab.EvaluateJavaScript(
@@ -46,6 +51,11 @@ class FormBasedCredentialsBackend(object):
     raise NotImplementedError()
 
   @property
+  def login_button_id(self):
+    """Some sites (like codepen) have a button to click to log in."""
+    return None
+
+  @property
   def login_input_id(self):
     raise NotImplementedError()
 
@@ -95,14 +105,14 @@ class FormBasedCredentialsBackend(object):
       tab.WaitForDocumentReadyStateToBeInteractiveOrBetter()

[tonyg, 2014/08/20 17:37:17]

Does changing this to Complete instead of Interactive help with the race?

[sullivan, 2014/08/21 21:55:23]

No, but I changed it anyway, since it seems like in general waiting a bit longer
makes things go a little smoother.

       logging.info('Loaded page: %s', url)
 
-      email_id = 'document.querySelector("#%s").%s.value = "%s"; ' % (
+      email_id = 'document.querySelector("#%s #%s").value = "%s"; ' % (
           self.login_form_id, self.login_input_id, config['username'])
-      password = 'document.querySelector("#%s").%s.value = "%s"; ' % (
+      password = 'document.querySelector("#%s #%s").value = "%s"; ' % (
           self.login_form_id, self.password_input_id, config['password'])
       tab.ExecuteJavaScript(email_id)
       tab.ExecuteJavaScript(password)
 
-      _SubmitFormAndWait(self.login_form_id, tab)
+      _SubmitFormAndWait(self.login_form_id, self.login_button_id, tab)
 
       self._logged_in = True
       return True