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

chrome/browser/policy/cloud/component_cloud_policy_browsertest.cc

 // Copyright (c) 2013 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 <string>
 
 #include "base/base64.h"
 #include "base/command_line.h"
 #include "base/file_util.h"
 #include "base/files/file_path.h"
@@ skipping 196 matching lines @@
     run_loop.Run();
     Mock::VerifyAndClearExpectations(&observer);
     policy_manager->core()->client()->RemoveObserver(&observer);
   }
 
 #if !defined(OS_CHROMEOS)
   void SignOut() {
     SigninManager* signin_manager =
         SigninManagerFactory::GetForProfile(browser()->profile());
     ASSERT_TRUE(signin_manager);
-    signin_manager->SignOut();
+    signin_manager->SignOut(signin_metrics::SIGNOUT_TEST);
   }
 #endif
 
   void RefreshPolicies() {
     ProfilePolicyConnector* profile_connector =
         ProfilePolicyConnectorFactory::GetForProfile(browser()->profile());
     PolicyService* policy_service = profile_connector->policy_service();
     base::RunLoop run_loop;
     policy_service->RefreshPolicies(run_loop.QuitClosure());
     run_loop.Run();
@@ skipping 110 matching lines @@
   ExtensionTestMessageListener signin_policy_listener(kTestPolicyJSON, true);
   event_listener2.Reply("get-policy-Name");
   EXPECT_TRUE(signin_policy_listener.WaitUntilSatisfied());
 
   // And the cache is back.
   EXPECT_TRUE(base::PathExists(cache_path));
 }
 #endif
 
 }  // namespace policy