Create component to expose network usage stats to consumers.

components/data_usage/PRESUBMIT.py

Index: components/data_usage/PRESUBMIT.py
diff --git a/components/password_manager/PRESUBMIT.py b/components/data_usage/PRESUBMIT.py
similarity index 87%
copy from components/password_manager/PRESUBMIT.py
copy to components/data_usage/PRESUBMIT.py
index c48fc83c15224f7215d1ce0f0d3867fbb3d9dfbd..60e8fdfb4871c14c0153e1b9188593c00ffa36eb 100644
--- a/components/password_manager/PRESUBMIT.py
+++ b/components/data_usage/PRESUBMIT.py
@@ -2,7 +2,7 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-"""Presubmit script for components/password_manager
+"""Top-level presubmit script for the data_usage component.
 
 See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts
 for more details about the presubmit API built into depot_tools.