Fix for flakiness in pyauto automation hook WaitForDownloadsToComplete.

chrome/test/functional/test_utils.py

 #!/usr/bin/python
 
 # Copyright (c) 2011 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import copy
 import email
 import logging
 import os
 import platform
 import smtplib
 import subprocess
 import types
 
 import pyauto_functional
 import pyauto
 import pyauto_utils
 
 
 """Commonly used functions for PyAuto tests."""
 
 def DownloadFileFromDownloadsDataDir(test, file_name):
-  """Download a file from downloads data directory, in first tab first window.
+  """Download a file from downloads data directory, in first tab, first window.
 
   Args:
-    test: derived from pyauto.PyUITest - base class for UI test cases
-    file_name: name of file to download
+    test: derived from pyauto.PyUITest - base class for UI test cases.
+    file_name: name of file to download.
   """
   file_url = test.GetFileURLForDataPath(os.path.join('downloads', file_name))
   downloaded_pkg = os.path.join(test.GetDownloadDirectory().value(),
                                 file_name)
   # Check if file already exists. If so then delete it.
   if os.path.exists(downloaded_pkg):
     RemoveDownloadedTestFile(test, file_name)
+  pre_download_ids = [x['id'] for x in test.GetDownloadsInfo().Downloads()]
   test.DownloadAndWaitForStart(file_url)
-  test.WaitForAllDownloadsToComplete()
+  test.WaitForAllDownloadsToComplete(pre_download_ids)
 
 
 def RemoveDownloadedTestFile(test, file_name):
   """Delete a file from the downloads directory.
 
   Arg:
     test: derived from pyauto.PyUITest - base class for UI test cases
     file_name: name of file to remove
   """
   downloaded_pkg = os.path.join(test.GetDownloadDirectory().value(),
@@ skipping 248 matching lines @@
     system_name = 'win'
   elif pyauto.PyUITest.IsLinux():
     system_name = 'linux'
   elif pyauto.PyUITest.IsMac():
     system_name = 'mac'
   else:
     return None
   node = platform.uname()[1].split('.')[0]
   creds_key = 'test_google_acct_%s_%s' % (system_name, node)
   return creds_key