Connect to stackdriver to fetch logs of each suite-scheduler run.

BUG=chromium:781379
TEST=Ran
'http://localhost:8080/test/stackdriverLogging?start_time=2017-11-1T17:30:00Z&end_time=2017-11-1T18:00:00Z&resource=/cron/test_push'.

Change-Id: Id84fdf6c79f73b7e04ec375e82cc016288c74b1e
diff --git a/rest_client.py b/rest_client.py
index d8545ac..0f1b20c 100644
--- a/rest_client.py
+++ b/rest_client.py
@@ -154,6 +154,34 @@
         body=input_event).execute()
 
 
+class StackdriverRestClient(object):
+  """REST client for google storage API."""
+
+  def __init__(self, rest_client):
+    """Initialize a REST client for connecting to Google storage API."""
+    self._rest_client = rest_client
+    self._rest_client.create_service()
+
+  def read_logs(self, request):
+   # project_id, page_size, order_by, query_filter=''):
+    """Read the logs of the project_id based on all filters.
+
+    Args:
+      request: a request dict generated by
+        stackdriver_lib.form_logging_client_request.
+
+    Returns:
+      A json object, can be parsed by
+        stackdriver_lib.parse_logging_client_response.
+
+    Raises:
+      apiclient.errors.HttpError
+    """
+    req = self._rest_client.service.entries().list(
+        fields='entries/protoPayload', body=request)
+    return req.execute()
+
+
 class SwarmingRestClient(object):
   """REST client for swarming proxy API."""