Remove MetricsServiceObserver in favor of MetricsProvider.

components/metrics/metrics_service_observer.cc

Index: components/metrics/metrics_service_observer.cc
diff --git a/components/metrics/metrics_service_observer.cc b/components/metrics/metrics_service_observer.cc
deleted file mode 100644
index e7116f839cefc83171650a5aa8bf45765b379b38..0000000000000000000000000000000000000000
--- a/components/metrics/metrics_service_observer.cc
+++ /dev/null
@@ -1,15 +0,0 @@
-// Copyright 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.
-
-#include "components/metrics/metrics_service_observer.h"
-
-namespace metrics {
-
-MetricsServiceObserver::MetricsServiceObserver() {
-}
-
-MetricsServiceObserver::~MetricsServiceObserver() {
-}
-
-}  // namespace metrics