cros: Add enterprise user session metrics

chrome/browser/chromeos/login/enterprise_user_session_metrics.cc

+// Copyright 2017 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 "chrome/browser/chromeos/login/enterprise_user_session_metrics.h"
+
+#include "base/logging.h"
+#include "base/metrics/histogram_macros.h"
+#include "chrome/browser/browser_process.h"
+#include "chrome/browser/chromeos/policy/browser_policy_connector_chromeos.h"
+#include "chrome/common/pref_names.h"
+#include "chromeos/login/auth/user_context.h"
+#include "components/prefs/pref_registry_simple.h"
+#include "components/prefs/pref_service.h"
+
+namespace {
+
+// Returns true if the device is enterprise managed, false otherwise.
+bool IsEnterpriseManaged() {
+  policy::BrowserPolicyConnectorChromeOS* connector =
+      g_browser_process->platform_part()->browser_policy_connector_chromeos();
+  return connector->IsEnterpriseManaged();

[achuithb, 2017/02/15 10:54:57]

Any reason to not have this all be one line?
return
g_browser_process->platform_part()->browser_policy_connector_chromeos()->IsEnterpriseManaged();

[xiyuan, 2017/02/15 19:08:10]

Done. Also updated the same util function in AppLaunchController.

+}
+
+}  // namespace
+
+namespace chromeos {
+namespace enterprise_user_session_metrics {
+
+void RegisterPrefs(PrefRegistrySimple* registry) {
+  registry->RegisterIntegerPref(prefs::kLastSessionType, 0);
+  registry->RegisterInt64Pref(prefs::kLastSessionLength, 0);
+}
+
+void RecordSignInEvent(SignInEventType sign_in_event_type) {
+  DCHECK(IsEnterpriseManaged());
+
+  UMA_HISTOGRAM_ENUMERATION("Enterprise.UserSession.Logins", sign_in_event_type,
+                            SIGN_IN_EVENT_COUNT);
+}
+
+void RecordSignInEvent(const UserContext& user_context, bool is_auto_login) {
+  DCHECK(IsEnterpriseManaged());
+
+  const user_manager::UserType session_type = user_context.GetUserType();
+  if (session_type == user_manager::USER_TYPE_REGULAR) {
+    RecordSignInEvent(REGULAR_USER);
+  } else if (session_type == user_manager::USER_TYPE_PUBLIC_ACCOUNT) {
+    RecordSignInEvent(is_auto_login ? AUTOMATIC_PUBLIC_SESSSION
+                                    : MANUAL_PUBLIC_SESSION);
+  }
+
+  // Kiosk sign-ins are handled separately in AppLaunchController and other
+  // session types are ignored for now.
+}
+
+void StoreSessionLength(user_manager::UserType session_type,
+                        const base::TimeDelta& session_length) {
+  DCHECK(IsEnterpriseManaged());
+
+  PrefService* local_state = g_browser_process->local_state();
+  local_state->SetInteger(prefs::kLastSessionType, session_type);
+  local_state->SetInt64(prefs::kLastSessionLength,
+                        session_length.ToInternalValue());
+  local_state->CommitPendingWrite();
+}
+
+void RecordStoredSessionLength() {
+  DCHECK(IsEnterpriseManaged());
+
+  PrefService* local_state = g_browser_process->local_state();
+  if (!local_state->HasPrefPath(prefs::kLastSessionType) ||
+      !local_state->HasPrefPath(prefs::kLastSessionLength)) {
+    return;
+  }
+
+  const user_manager::UserType session_type =
+      static_cast<user_manager::UserType>(
+          local_state->GetInteger(prefs::kLastSessionType));
+  const base::TimeDelta session_length = base::TimeDelta::FromInternalValue(
+      local_state->GetInt64(prefs::kLastSessionLength));
+
+  local_state->ClearPref(prefs::kLastSessionType);
+  local_state->ClearPref(prefs::kLastSessionLength);
+
+  if (session_length.is_zero())
+    return;
+
+  std::string metric_name;
+  if (session_type == user_manager::USER_TYPE_REGULAR) {
+    metric_name = "Enterprise.RegularSession.SessionLength";
+  } else if (session_type == user_manager::USER_TYPE_PUBLIC_ACCOUNT) {
+    metric_name = "Enterprise.PublicSession.SessionLength";

[Ilya Sherman, 2017/02/15 00:16:57]

Metric names used with histogram macros must be runtime constant.  Are these
runtime constants for the browser process?

[xiyuan, 2017/02/15 19:08:10]

Acknowledged. Changed use UMA_HISTOGRAM_SPARSE_SLOWLY below.

+  } else {
+    // No session length metric for other session types.
+    return;
+  }
+
+  // Report session duration for the first 24 hours, split into 144 buckets
+  // (i.e. every 10 minute). Use counts rather than time to track in
+  // minutes.

[Ilya Sherman, 2017/02/15 00:16:57]

Note that histogram buckets are logarithmically spaced, so they won't actually
be every 10 minutes.  Perhaps you want to use a sparse histogram, capped at 24
hours?  You then don't need to worry about the runtime constant name issue
either.

[xiyuan, 2017/02/15 19:08:10]

Always has something to learn. :)
Changed to UMA_HISTOGRAM_SPARSE_SLOWLY with session length capped to 24 hours
and converted to a 10-minute bucket number to report.

+  UMA_HISTOGRAM_CUSTOM_COUNTS(metric_name, session_length.InMinutes(), 0,
+                              base::TimeDelta::FromHours(24).InMinutes(), 144);
+}
+
+}  // namespace enterprise_user_session_metrics
+}  // namespace chromeos