[Findit] Support sending cookies for http requests.

tools/findit/common/http_client.py

+# Copyright (c) 2014 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.
+
+class HttpClient(object):
+  """Represent a http client for sending request to a http[s] server.
+
+  If cookies need to be sent, they should be in a file pointed to by
+  COOKIE_FILE in the environment.
+  """
+
+  @staticmethod
+  def Get(url, params={}, timeout=None):
+    """Send a GET request to the given url with the given parameters.
+
+    Returns:
+      (status_code, data)
+      state_code: the http status code in the response.
+      data: the body of the response.
+    """
+    raise NotImplemented()