[iOS] Upstream some stability code

ios/chrome/browser/metrics/ios_stability_metrics_provider.h

+// Copyright 2015 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 IOS_CHROME_BROWSER_METRICS_IOS_STABILITY_METRICS_PROVIDER_H_
+#define IOS_CHROME_BROWSER_METRICS_IOS_STABILITY_METRICS_PROVIDER_H_
+
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "components/metrics/metrics_provider.h"
+
+namespace metrics {
+class MetricsService;
+}
+
+// Exposed for testing purposes only.
+// Values of the UMA Stability.MobileSessionShutdownType histogram.
+enum MobileSessionShutdownType {
+  SHUTDOWN_IN_BACKGROUND = 0,
+  SHUTDOWN_IN_FOREGROUND_NO_CRASH_LOG_NO_MEMORY_WARNING,
+  SHUTDOWN_IN_FOREGROUND_WITH_CRASH_LOG_NO_MEMORY_WARNING,
+  SHUTDOWN_IN_FOREGROUND_NO_CRASH_LOG_WITH_MEMORY_WARNING,
+  SHUTDOWN_IN_FOREGROUND_WITH_CRASH_LOG_WITH_MEMORY_WARNING,
+  FIRST_LAUNCH_AFTER_UPGRADE,
+  MOBILE_SESSION_SHUTDOWN_TYPE_COUNT,
+};
+
+class IOSStabilityMetricsProvider : public metrics::MetricsProvider {
+ public:
+  explicit IOSStabilityMetricsProvider(
+      metrics::MetricsService* metrics_service);
+  ~IOSStabilityMetricsProvider() override;
+
+  // metrics::MetricsProvider
+  bool HasInitialStabilityMetrics() override;
+  void ProvideInitialStabilityMetrics(
+      metrics::SystemProfileProto* system_profile_proto) override;
+
+ protected:
+  // Provides information on the last session environment, used to decide what
+  // stability metrics to provide in ProvideInitialStabilityMetrics.
+  // These methods are virtual to be overridden in the tests.
+  // The default implementations return the real values.
+
+  // Whether this is the first time the app is launched after an upgrade.
+  virtual bool IsFirstLaunchAfterUpgrade();
+
+  // Whether there are crash reports to upload.
+  virtual bool HasCrashLogs();
+
+  // Whether there were crash reports that have been uploaded in background
+  // since the last full start.
+  virtual bool HasUploadedCrashReportsInBackground();
+
+  // Whether there was a memory warning shortly before last shutdown.
+  virtual bool ReceivedMemoryWarningBeforeLastShutdown();
+
+ private:
+  metrics::MetricsService* metrics_service_;
+  DISALLOW_COPY_AND_ASSIGN(IOSStabilityMetricsProvider);
+};
+
+#endif  // IOS_CHROME_BROWSER_METRICS_IOS_STABILITY_METRICS_PROVIDER_H_