Track when and how a profile is signed out via UMA.

chrome/browser/policy/cloud/user_policy_signin_service_unittest.cc

Index: chrome/browser/policy/cloud/user_policy_signin_service_unittest.cc
diff --git a/chrome/browser/policy/cloud/user_policy_signin_service_unittest.cc b/chrome/browser/policy/cloud/user_policy_signin_service_unittest.cc
index 5a9d019dfe63f509ccf854eae3c30b58ea3167d5..d78256e12940486a3e209235b3bfd8967db14ab0 100644
--- a/chrome/browser/policy/cloud/user_policy_signin_service_unittest.cc
+++ b/chrome/browser/policy/cloud/user_policy_signin_service_unittest.cc
@@ -88,7 +88,7 @@ class SigninManagerFake : public FakeSigninManager {
   void ForceSignOut() {
     // Allow signing out now.
     prohibit_signout_ = false;
-    SignOut();
+    SignOut(signin_metrics::SIGNOUT_TEST);
   }
 
   static KeyedService* Build(content::BrowserContext* profile) {
@@ -576,7 +576,8 @@ TEST_F(UserPolicySigninServiceSignedInTest, SignOutAfterInit) {
   EXPECT_CALL(*mock_store_, Clear());
 
   // Now sign out.
-  SigninManagerFactory::GetForProfile(profile_.get())->SignOut();
+  SigninManagerFactory::GetForProfile(profile_.get())->SignOut(
+      signin_metrics::SIGNOUT_TEST);
 
   // UserCloudPolicyManager should be shut down.
   ASSERT_FALSE(manager_->core()->service());