Work around download system breakpage by using WaitUntil on pyauto side.

chrome/test/functional/downloads.py

Index: chrome/test/functional/downloads.py
diff --git a/chrome/test/functional/downloads.py b/chrome/test/functional/downloads.py
index 5ec54844465c3364aba6e889f917ba518d94a03e..1af21c807db6a0a5ebd26acc8c84e21482e099e2 100644
--- a/chrome/test/functional/downloads.py
+++ b/chrome/test/functional/downloads.py
@@ -200,8 +200,12 @@ class DownloadsTest(pyauto.PyUITest):
       self.DownloadAndWaitForStart(file_url)
       # Waiting for big file to download might exceed automation timeout.
       # Temporarily increase the automation timeout.
-      self._CallFunctionWithNewTimeout(4 * 60 * 1000,  # 4 min.
-                                       self.WaitForAllDownloadsToComplete)
+
+      # Temp workaround for crbug.com/54131
+      # self._CallFunctionWithNewTimeout(4 * 60 * 1000,  # 4 min.
+      #                                  self.WaitForAllDownloadsToComplete)
+      self.WaitForAllDownloadsToComplete(timeout=4*60*1000)
+      # -- End workaround
       # Verify that the file was correctly downloaded
       self.assertTrue(os.path.exists(downloaded_pkg),
                       'Downloaded file %s missing.' % downloaded_pkg)