telemetry: Complete transition of cros_interface import path.

CL:287163 began transition of the import path for cros_interface module
provided by telemetry. With the new path now available in CrOS (after a
chrome roll), this CL completes the transition to the new path, dropping
the old one.

BUG=chromium:512427
TEST=CQ passes.

Change-Id: If470bc11c2d61993008ae6cbafee7fa5838a57e2
Reviewed-on: https://chromium-review.googlesource.com/287144
Reviewed-by: mukesh agrawal <quiche@chromium.org>
Reviewed-by: Don Garrett <dgarrett@chromium.org>
Reviewed-by: Prathmesh Prabhu <pprabhu@chromium.org>
Commit-Queue: Prathmesh Prabhu <pprabhu@chromium.org>
Tested-by: Prathmesh Prabhu <pprabhu@chromium.org>
diff --git a/client/common_lib/cros/chrome.py b/client/common_lib/cros/chrome.py
index a688f2d..e6315c6 100644
--- a/client/common_lib/cros/chrome.py
+++ b/client/common_lib/cros/chrome.py
@@ -6,13 +6,7 @@
 
 from autotest_lib.client.cros import constants
 from autotest_lib.client.bin import utils
-from telemetry.core import exceptions, util
-# Need to support both paths for the transition (crbug.com/512427).
-try:
-  from telemetry.core.platform import cros_interface
-except ImportError:
-  from telemetry.core import cros_interface
-
+from telemetry.core import cros_interface, exceptions, util
 from telemetry.internal.browser import browser_finder, browser_options
 from telemetry.internal.browser import extension_to_load