Add a new GetInstance() method for singleton classes under chrome/service and /net.

net/base/bandwidth_metrics.cc

Index: net/base/bandwidth_metrics.cc
diff --git a/net/base/bandwidth_metrics.cc b/net/base/bandwidth_metrics.cc
new file mode 100644
index 0000000000000000000000000000000000000000..eaaa3c01b89a267881f076d01ddbe4fc67b9afb1
--- /dev/null
+++ b/net/base/bandwidth_metrics.cc
@@ -0,0 +1,15 @@
+// Copyright (c) 2010 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.
+
+#include "base/singleton.h"
+#include "net/base/bandwidth_metrics.h"
+
+namespace net {
+
+ScopedBandwidthMetrics::ScopedBandwidthMetrics()
+    : metrics_(Singleton<BandwidthMetrics>::get()),
+      started_(false) {
+}
+
+}  // namespace net