[iOS] Upstream some stability code

ios/chrome/browser/metrics/ios_stability_metrics_provider.mm

Index: ios/chrome/browser/metrics/ios_stability_metrics_provider.mm
diff --git a/ios/chrome/browser/metrics/ios_stability_metrics_provider.mm b/ios/chrome/browser/metrics/ios_stability_metrics_provider.mm
new file mode 100644
index 0000000000000000000000000000000000000000..cc1af0be6c364d41ee19695630f379f62a5b78ab
--- /dev/null
+++ b/ios/chrome/browser/metrics/ios_stability_metrics_provider.mm
@@ -0,0 +1,91 @@
+// 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.
+
+#include "ios/chrome/browser/metrics/ios_stability_metrics_provider.h"
+
+#include <Foundation/Foundation.h>
+
+#include "base/logging.h"
+#include "base/metrics/histogram_macros.h"
+#include "components/metrics/metrics_service.h"
+#include "ios/chrome/browser/crash_report/breakpad_helper.h"
+#import "ios/chrome/browser/crash_report/crash_report_background_uploader.h"
+#import "ios/chrome/browser/metrics/previous_session_info.h"
+
+namespace {
+
+// Logs |type| in the shutdown type histogram.
+void LogShutdownType(MobileSessionShutdownType type) {
+  UMA_STABILITY_HISTOGRAM_ENUMERATION("Stability.MobileSessionShutdownType",
+                                      type, MOBILE_SESSION_SHUTDOWN_TYPE_COUNT);
+}
+
+}  // namespace
+
+IOSStabilityMetricsProvider::IOSStabilityMetricsProvider(
+    metrics::MetricsService* metrics_service)
+    : metrics_service_(metrics_service) {
+  DCHECK(metrics_service_);
+}
+
+IOSStabilityMetricsProvider::~IOSStabilityMetricsProvider() {
+}
+
+bool IOSStabilityMetricsProvider::HasInitialStabilityMetrics() {
+  return true;
+}
+
+void IOSStabilityMetricsProvider::ProvideInitialStabilityMetrics(
+    metrics::SystemProfileProto* system_profile_proto) {
+  // If this is the first launch after an upgrade, existing crash reports
+  // may have been deleted before this code runs, so log this case in its
+  // own bucket.
+  if (IsFirstLaunchAfterUpgrade()) {
+    LogShutdownType(FIRST_LAUNCH_AFTER_UPGRADE);
+    return;
+  }
+
+  // If the last app lifetime did not end with a crash, then log it as a
+  // normal shutdown while in the background.
+  if (metrics_service_->WasLastShutdownClean()) {
+    LogShutdownType(SHUTDOWN_IN_BACKGROUND);
+    return;
+  }
+
+  // If the last app lifetime ended in a crash, log the type of crash.
+  MobileSessionShutdownType shutdown_type;
+  const bool with_crash_log =
+      HasUploadedCrashReportsInBackground() || HasCrashLogs();
+  if (ReceivedMemoryWarningBeforeLastShutdown()) {
+    if (with_crash_log) {
+      shutdown_type = SHUTDOWN_IN_FOREGROUND_WITH_CRASH_LOG_WITH_MEMORY_WARNING;
+    } else {
+      shutdown_type = SHUTDOWN_IN_FOREGROUND_NO_CRASH_LOG_WITH_MEMORY_WARNING;
+    }
+  } else {
+    if (with_crash_log) {
+      shutdown_type = SHUTDOWN_IN_FOREGROUND_WITH_CRASH_LOG_NO_MEMORY_WARNING;
+    } else {
+      shutdown_type = SHUTDOWN_IN_FOREGROUND_NO_CRASH_LOG_NO_MEMORY_WARNING;
+    }
+  }
+  LogShutdownType(shutdown_type);
+}
+
+bool IOSStabilityMetricsProvider::IsFirstLaunchAfterUpgrade() {
+  return [[PreviousSessionInfo sharedInstance] isFirstSessionAfterUpgrade];
+}
+
+bool IOSStabilityMetricsProvider::HasCrashLogs() {
+  return breakpad_helper::HasReportToUpload();
+}
+
+bool IOSStabilityMetricsProvider::HasUploadedCrashReportsInBackground() {
+  return [CrashReportBackgroundUploader hasUploadedCrashReportsInBackground];
+}
+
+bool IOSStabilityMetricsProvider::ReceivedMemoryWarningBeforeLastShutdown() {
+  return [[PreviousSessionInfo sharedInstance]
+      didSeeMemoryWarningShortlyBeforeTerminating];
+}