Introduce CrosBrowserWithOOBE, which exposes an oobe property.

tools/telemetry/telemetry/core/backends/chrome/cros_browser_with_oobe.py

Index: tools/telemetry/telemetry/core/backends/chrome/cros_browser_with_oobe.py
diff --git a/tools/telemetry/telemetry/core/backends/chrome/cros_browser_with_oobe.py b/tools/telemetry/telemetry/core/backends/chrome/cros_browser_with_oobe.py
new file mode 100644
index 0000000000000000000000000000000000000000..0e401ebf09059bb8bc973c5ab36ad47d8dc76353
--- /dev/null
+++ b/tools/telemetry/telemetry/core/backends/chrome/cros_browser_with_oobe.py
@@ -0,0 +1,19 @@
+# Copyright (c) 2013 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.
+
+from telemetry.core import browser
+from telemetry.core.backends.chrome import cros_browser_backend
+
+class CrOSBrowserWithOOBE(browser.Browser):
+  """Cros-specific browser."""
+  def __init__(self, backend, platform_backend):
+    assert isinstance(backend, cros_browser_backend.CrOSBrowserBackend)
+    super(CrOSBrowserWithOOBE, self).__init__(backend, platform_backend)
+
+  @property
+  def oobe(self):
+    """The login webui (also serves as ui for screenlock and
+    out-of-box-experience).
+    """
+    return self._browser_backend.oobe