upload_symbols: Fix api calls changed by swarming.client upgrade.

BUG=chromium:808149
TEST=Ran unittest.

Change-Id: I1fa02282044d919634e55fe30831c1fd12ada49a
Reviewed-on: https://chromium-review.googlesource.com/1079720
Reviewed-by: Jason Clinton <jclinton@chromium.org>
Commit-Queue: Xixuan Wu <xixuan@chromium.org>
Tested-by: Xixuan Wu <xixuan@chromium.org>
diff --git a/scripts/upload_symbols.py b/scripts/upload_symbols.py
index 8fa55ff..0488a83 100644
--- a/scripts/upload_symbols.py
+++ b/scripts/upload_symbols.py
@@ -63,6 +63,7 @@
 # try to import & connect to a dbus server.  That's a waste of time.
 sys.modules['keyring'] = None
 # And our sys.path muckery confuses pylint.
+import isolate_storage  # pylint: disable=import-error
 import isolateserver  # pylint: disable=import-error
 
 
@@ -347,8 +348,8 @@
   """
   try:
     with timeout_util.Timeout(DEDUPE_TIMEOUT):
-      return isolateserver.get_storage_api(constants.ISOLATESERVER,
-                                           dedupe_namespace)
+      return isolate_storage.get_storage_api(constants.ISOLATESERVER,
+                                             dedupe_namespace)
   except Exception:
     logging.warning('initializing isolate server connection failed',
                     exc_info=True)