Notify page load metrics when the app enters the background.

chrome/browser/metrics/page_load_metrics_provider.h

+// Copyright 2016 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.
+
+#ifndef CHROME_BROWSER_METRICS_PAGE_LOAD_METRICS_PROVIDER_H_
+#define CHROME_BROWSER_METRICS_PAGE_LOAD_METRICS_PROVIDER_H_
+
+#include "base/macros.h"
+#include "components/metrics/metrics_provider.h"
+
+// MetricsProvider that interfaces with page_load_metrics. Note that this class
+// is currently only used on Android.
+class PageLoadMetricsProvider : public metrics::MetricsProvider {
+ public:
+  PageLoadMetricsProvider();
+  ~PageLoadMetricsProvider() override;
+
+  // metrics:MetricsProvider:
+  void OnAppEnterBackground() override;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(PageLoadMetricsProvider);
+};
+
+#endif  // CHROME_BROWSER_METRICS_PAGE_LOAD_METRICS_PROVIDER_H_