make version of ts_mon compatible with appengine

infra_libs/ts_mon/common/metrics.py

 # Copyright 2015 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.
 
 """Classes representing individual metrics that can be sent."""
 
 
 import copy
 import threading
 import time
 
-from monacq.proto import metrics_pb2
-
-from infra_libs.ts_mon import distribution
-from infra_libs.ts_mon import errors
-from infra_libs.ts_mon import interface
+try:
+  from infra_libs.ts_mon import interface
+  from infra_libs.ts_mon.common import distribution
+  from infra_libs.ts_mon.common import errors
+  from monacq.proto import metrics_pb2
+except ImportError:
+  from gae_ts_mon import interface
+  from gae_ts_mon.common import distribution
+  from gae_ts_mon.common import errors
+  from gae_ts_mon.proto import metrics_pb2
 
 
 MICROSECONDS_PER_SECOND = 1000000
 
 
 class Metric(object):
   """Abstract base class for a metric.
 
   A Metric is an attribute that may be monitored across many targets. Examples
   include disk usage or the number of requests a server has received. A single
@@ skipping 398 matching lines @@
 
   def __init__(
       self, name, bucketer=None, target=None, fields=None, time_fn=time.time):
     super(NonCumulativeDistributionMetric, self).__init__(
         name,
         is_cumulative=False,
         bucketer=bucketer,
         target=target,
         fields=fields,
         time_fn=time_fn)