Fixed race condition in media_stream_infobar.py.

chrome/test/functional/webrtc_test_base.py

+#!/usr/bin/env python
+# Copyright (c) 2012 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 pyauto
+
+
+class WebrtcTestBase(pyauto.PyUITest):
+  """This base class provides helpers for getUserMedia calls."""
+
+  def WaitForGetUserMediaResult(self, tab_index):
+    """Waits until WebRTC has responded to a getUserMedia query.
+
+    Fails an assert if WebRTC doesn't respond within the default timeout.
+
+    Args:
+      tab_index: the tab to query.
+    """
+    def HasResult():
+      return self.GetUserMediaResult(tab_index) != 'not-called-yet'
+    self.assertTrue(self.WaitUntil(HasResult),
+                    msg='Timed out while waiting for getUserMedia callback.')
+
+  def GetUserMediaResult(self, tab_index):
+    """Retrieves WebRTC's answer to a user media query.
+
+    Args:
+      tab_index: the tab to query.
+
+    Returns:
+      Specified in obtainGetUserMediaResult() in getusermedia.js.
+    """
+    return self.ExecuteJavascript(
+        'obtainGetUserMediaResult()', tab_index=tab_index)