Add metrics for signin in Ephemeral Guest profiles.

"Profile.EphemeralGuest.Signin" metric is recorded when user signs in
to or signs out from a GAIA account in an ephemeral Guest profile.

Bug: 1167474, 1148695
Change-Id: Ib0aa6660c2663083b740a6c393243a0058be78c0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2632694
Auto-Submit: Ramin Halavati <rhalavati@chromium.org>
Commit-Queue: Brian White <bcwhite@chromium.org>
Reviewed-by: Brian White <bcwhite@chromium.org>
Reviewed-by: David Roger <droger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#845705}

chrome/browser/BUILD.gn

@@ -1437,6 +1437,8 @@ static_library("browser") {
     "profiles/gaia_info_update_service_factory.h",
     "profiles/guest_mode_policy_handler.cc",
     "profiles/guest_mode_policy_handler.h",
+    "profiles/guest_signin_observer_factory.cc",
+    "profiles/guest_signin_observer_factory.h",
     "profiles/incognito_helpers.cc",
     "profiles/incognito_helpers.h",
     "profiles/incognito_mode_policy_handler.cc",

chrome/browser/profiles/chrome_browser_main_extra_parts_profiles.cc

@@ -66,6 +66,7 @@
 #include "chrome/browser/prefs/pref_metrics_service.h"
 #include "chrome/browser/privacy_sandbox/privacy_sandbox_settings_factory.h"
 #include "chrome/browser/profiles/gaia_info_update_service_factory.h"
+#include "chrome/browser/profiles/guest_signin_observer_factory.h"
 #include "chrome/browser/profiles/renderer_updater_factory.h"
 #include "chrome/browser/safe_browsing/certificate_reporting_service_factory.h"
 #include "chrome/browser/search/suggestions/suggestions_service_factory.h"
@@ -238,6 +239,7 @@ void ChromeBrowserMainExtraPartsProfiles::
   AboutSigninInternalsFactory::GetInstance();
 #if !defined(OS_ANDROID)
   AccessContextAuditServiceFactory::GetInstance();
+  GuestSigninObserverFactory::GetInstance();
 #endif
   AccountConsistencyModeManagerFactory::GetInstance();
   AccountInvestigatorFactory::GetInstance();

chrome/browser/profiles/guest_signin_observer_factory.cc

+// Copyright 2021 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/profiles/guest_signin_observer_factory.h"
+
+#include "base/memory/singleton.h"
+#include "base/metrics/histogram_functions.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/signin/identity_manager_factory.h"
+#include "components/keyed_service/content/browser_context_dependency_manager.h"
+#include "components/signin/public/identity_manager/identity_manager.h"
+
+namespace {
+
+class GuestSigninObserver : public KeyedService,
+                            public signin::IdentityManager::Observer {
+ public:
+  explicit GuestSigninObserver(Profile* profile) : profile_(profile) {
+    IdentityManagerFactory::GetForProfile(profile)->AddObserver(this);
+  }
+
+  void Shutdown() override {
+    IdentityManagerFactory::GetForProfile(profile_)->RemoveObserver(this);
+  }
+
+  void OnPrimaryAccountChanged(
+      const signin::PrimaryAccountChangeEvent& event) override {
+    switch (event.GetEventTypeFor(signin::ConsentLevel::kNotRequired)) {
+      case signin::PrimaryAccountChangeEvent::Type::kSet:
+        base::UmaHistogramBoolean("Profile.EphemeralGuest.Signin", true);
+        break;
+      case signin::PrimaryAccountChangeEvent::Type::kCleared:
+        base::UmaHistogramBoolean("Profile.EphemeralGuest.Signin", false);
+        break;
+      case signin::PrimaryAccountChangeEvent::Type::kNone:
+        break;
+    }
+  }
+
+ private:
+  Profile* profile_;
+};
+
+}  // namespace
+
+// static
+GuestSigninObserverFactory* GuestSigninObserverFactory::GetInstance() {
+  return base::Singleton<GuestSigninObserverFactory>::get();
+}
+
+GuestSigninObserverFactory::GuestSigninObserverFactory()
+    : BrowserContextKeyedServiceFactory(
+          "GuestSigninObserver",
+          BrowserContextDependencyManager::GetInstance()) {
+  DependsOn(IdentityManagerFactory::GetInstance());
+}
+
+KeyedService* GuestSigninObserverFactory::BuildServiceInstanceFor(
+    content::BrowserContext* context) const {
+  Profile* profile(Profile::FromBrowserContext(context));
+  if (profile->IsEphemeralGuestProfile())
+    return new GuestSigninObserver(profile);
+  return nullptr;
+}
+
+bool GuestSigninObserverFactory::ServiceIsCreatedWithBrowserContext() const {
+  return true;
+}

chrome/browser/profiles/guest_signin_observer_factory.h

+// Copyright 2021 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_PROFILES_GUEST_SIGNIN_OBSERVER_FACTORY_H_
+#define CHROME_BROWSER_PROFILES_GUEST_SIGNIN_OBSERVER_FACTORY_H_
+
+#include "components/keyed_service/content/browser_context_keyed_service_factory.h"
+
+namespace base {
+template <typename T>
+struct DefaultSingletonTraits;
+}  // namespace base
+
+// Factory for BrowserKeyedService GuestSigninObserver.
+class GuestSigninObserverFactory : public BrowserContextKeyedServiceFactory {
+ public:
+  static GuestSigninObserverFactory* GetInstance();
+
+ private:
+  friend struct base::DefaultSingletonTraits<GuestSigninObserverFactory>;
+
+  GuestSigninObserverFactory();
+
+  // BrowserContextKeyedServiceFactory:
+  KeyedService* BuildServiceInstanceFor(
+      content::BrowserContext* context) const override;
+  bool ServiceIsCreatedWithBrowserContext() const override;
+
+  DISALLOW_COPY_AND_ASSIGN(GuestSigninObserverFactory);
+};
+
+#endif  // CHROME_BROWSER_PROFILES_GUEST_SIGNIN_OBSERVER_FACTORY_H_

tools/metrics/histograms/histograms_xml/profile/histograms.xml

@@ -197,6 +197,17 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
   </summary>
 </histogram>
 
+<histogram name="Profile.EphemeralGuest.Signin" enum="BooleanProfileSignedIn"
+    expires_after="2022-02-02">
+  <owner>rhalavati@chromium.org</owner>
+  <owner>chrome-privacy-core@google.com</owner>
+  <summary>
+    This histogram records if user's sign-in state to a GAIA account in an
+    Ephemeral Guest profile is changed. This is recorded when user signs in and
+    when user signs out in an Ephemeral Guest profile.
+  </summary>
+</histogram>
+
 <histogram name="Profile.ExtensionSize" units="MB" expires_after="2018-08-30">
   <owner>Please list the metric's owners. Add more owner tags as needed.</owner>
   <summary>Size of the extension cookies database.</summary>