Added a new PyAuto method WaitForDomNode() which allows tests to block until a specified node exist…

chrome/test/functional/apptest.py

Index: chrome/test/functional/apptest.py
diff --git a/chrome/test/functional/apptest.py b/chrome/test/functional/apptest.py
index b1abcbd1bd30536d5ebf5eff97b5d3b470c26479..1d09ef2bb5bde2f47faaa06a7564bc2b7d0f4475 100644
--- a/chrome/test/functional/apptest.py
+++ b/chrome/test/functional/apptest.py
@@ -24,11 +24,19 @@ class PyAutoEventsTest(pyauto.PyUITest):
     self.GetNextEvent(success_id)
 
   def testDomMutationEvents(self):
-    """Basic tests for Dom Mutation observers."""
+    """Basic tests for WaitForDomNode."""
+    url = self.GetHttpURLForDataPath('apptest', 'dom_mutations.html')
+    self.NavigateToURL(url)
+    self.WaitForDomNode(domselector.CSSSelector('#login'), 'Log In')
+    self.NewWebDriver().find_element_by_id('login').click()
+    self.WaitForDomNode(domselector.XPath('id(\'console\')'), '.*succeeded.*')
+
+  def testDomMutationObservers(self):
+    """Tests for the various types of Dom Mutation observers."""
     url = self.GetHttpURLForDataPath('apptest', 'dom_mutations.html')
     self.NavigateToURL(url)
     self.GetNextEvent(self.AddDomMutationObserver(
-        'add', domselector.XPath('/html/body')))
+        'exists', domselector.XPath('/html/body')))
     self.GetNextEvent(self.AddDomMutationObserver(
         'add', domselector.CSSSelector('#login'), expected_value='Log In'))
     success_id = self.AddDomMutationObserver(