Introduce AndroidMetricsProvider class.

chrome/browser/metrics/android_metrics_provider_android.h

Index: chrome/browser/metrics/android_metrics_provider_android.h
===================================================================
--- chrome/browser/metrics/android_metrics_provider_android.h	(revision 0)
+++ chrome/browser/metrics/android_metrics_provider_android.h	(working copy)
@@ -0,0 +1,44 @@
+// 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.
+
+#ifndef CHROME_BROWSER_METRICS_ANDROID_METRICS_PROVIDER_ANDROID_H_
+#define CHROME_BROWSER_METRICS_ANDROID_METRICS_PROVIDER_ANDROID_H_
+
+#include "base/basictypes.h"
+#include "chrome/browser/android/activity_type_ids.h"
+#include "components/metrics/metrics_provider.h"
+
+class PrefService;
+
+// AndroidMetricsProvider provides Android-specific stability metrics.
+class AndroidMetricsProvider : public metrics::MetricsProvider {
+ public:
+  // Creates the AndroidMetricsProvider with the given |local_state|.
+  explicit AndroidMetricsProvider(PrefService* local_state);
+  virtual ~AndroidMetricsProvider();
+
+  // Called when the Activity that the user interacts with is swapped out.
+  void OnForegroundActivityChanged(ActivityTypeIds::Type type);
+
+  // metrics::MetricsDataProvider:
+  virtual void ProvideStabilityMetrics(
+      metrics::SystemProfileProto_Stability* stability_proto) OVERRIDE;
+
+  // Registers local state prefs used by this class.
+  static void RegisterPrefs(PrefRegistrySimple* registry);
+
+ private:
+  // Called to log launch and crash stats to preferences.
+  void LogAndroidStabilityToPrefs();
+
+  // Converts crash stats stored in the preferences into histograms.
+  void ConvertAndroidStabilityPrefsToHistograms();

[Ilya Sherman, 2014/05/21 09:15:28]

nit: WDYT of dropping "Android" from these method names, given that they're
already in an Android-specific class?

[Alexei Svitkine (slow), 2014/05/21 09:48:47]

SGTM. Done.

+
+  // Weak pointer to the local state prefs store.
+  PrefService* local_state_;
+
+  DISALLOW_COPY_AND_ASSIGN(AndroidMetricsProvider);
+};
+
+#endif  // CHROME_BROWSER_METRICS_ANDROID_METRICS_PROVIDER_ANDROID_H_