Fix flakiness in pyauto test on ChromeOS: ntp.NTPTest.testThumbnailPersistence.

chrome/test/pyautolib/pyauto.py

Index: chrome/test/pyautolib/pyauto.py
diff --git a/chrome/test/pyautolib/pyauto.py b/chrome/test/pyautolib/pyauto.py
index 1ba07cb79e5e8cca8804c49017d6d7dbe54e0bdc..685d4f99fcdeec6412cf79ac5a41b2f622da1767 100644
--- a/chrome/test/pyautolib/pyauto.py
+++ b/chrome/test/pyautolib/pyauto.py
@@ -171,11 +171,43 @@ class PyUITest(pyautolib.PyUITestBase, unittest.TestCase):
   def tearDown(self):
     self.TearDown()  # Destroy browser
 
-  @staticmethod
-  def CloseChromeOnChromeOS():
+  def CloseChromeOnChromeOS(self):
     """Gracefully exit chrome on ChromeOS."""
+
+    def _GetListOfChromePids():
+      """Retrieves the list of currently-running Chrome process IDs.
+
+      Returns:
+        A list of strings, where each string represents a currently-running
+        'chrome' process ID.
+      """
+      proc = subprocess.Popen(['ps', '-C', 'chrome'], stdout=subprocess.PIPE)

[Nirnimesh, 2011/06/08 18:32:22]

'prep chrome' will be easier to parse

[dennis_jeffrey, 2011/06/08 21:50:31]

Awesome!  Thanks!

+      output, _ = proc.communicate()

[Nirnimesh, 2011/06/08 18:32:22]

output = proc.communicate()[0]

[dennis_jeffrey, 2011/06/08 21:50:31]

This line has since been removed.

+      pids = []
+      for line in output.split('\n'):
+        line = line.strip()
+        if line.find('chrome') >= 0:
+          pids.append(line[:line.find(' ')])
+      return pids
+
+    orig_pids = _GetListOfChromePids()
     subprocess.call(['pkill', 'chrome'])
 
+    def _DoesOldChromeProcessStillExist():

[Nirnimesh, 2011/06/08 18:32:22]

take orig_pids as arg

[dennis_jeffrey, 2011/06/08 21:50:31]

Done.

+      """Determines whether an originally-running 'chrome' process exists.
+
+      Returns:
+        True, if an originally-running 'chrome' process still exists, or
+        False otherwise.
+      """
+      new_pids = _GetListOfChromePids()
+      for new_pid in new_pids:

[Nirnimesh, 2011/06/08 18:32:22]

merge with previous line

[dennis_jeffrey, 2011/06/08 21:50:31]

Done.

+        if new_pid in orig_pids:
+          return True
+      return False
+
+    self.WaitUntil(lambda: not _DoesOldChromeProcessStillExist())

[Nirnimesh, 2011/06/08 18:32:22]

pass orig_pids as arg

[Nirnimesh, 2011/06/08 18:32:22]

Why the negation? Just invert the function --
lambda: _ArePIDsDead(orig_pids)

[dennis_jeffrey, 2011/06/08 21:50:31]

Done.

[dennis_jeffrey, 2011/06/08 21:50:31]

Done.

+
   def EnableChromeTestingOnChromeOS(self):
     """Enables the named automation interface on chromeos.