Add source column to chrome://policy showing the origins of policies.

chrome/browser/prefs/synced_pref_change_registrar_browsertest.cc

Index: chrome/browser/prefs/synced_pref_change_registrar_browsertest.cc
diff --git a/chrome/browser/prefs/synced_pref_change_registrar_browsertest.cc b/chrome/browser/prefs/synced_pref_change_registrar_browsertest.cc
index af9a3618807471c29c728c829ce3fe99aaa995be..1787383e126465d5d45f634e5511d5a1f0b69f2a 100644
--- a/chrome/browser/prefs/synced_pref_change_registrar_browsertest.cc
+++ b/chrome/browser/prefs/synced_pref_change_registrar_browsertest.cc
@@ -28,6 +28,7 @@
 #include "components/policy/core/browser/browser_policy_connector.h"
 #include "components/policy/core/common/mock_configuration_policy_provider.h"
 #include "components/policy/core/common/policy_map.h"
+#include "components/policy/core/common/policy_types.h"
 #include "policy/policy_constants.h"
 #endif
 
@@ -190,6 +191,7 @@ IN_PROC_BROWSER_TEST_F(SyncedPrefChangeRegistrarTest,
   policies.Set(policy::key::kShowHomeButton,
                policy::POLICY_LEVEL_MANDATORY,
                policy::POLICY_SCOPE_USER,
+               policy::POLICY_SOURCE_CLOUD,
                new base::FundamentalValue(true),
                NULL);
   UpdateChromePolicy(policies);
@@ -211,6 +213,7 @@ IN_PROC_BROWSER_TEST_F(SyncedPrefChangeRegistrarTest,
   policies.Set(policy::key::kShowHomeButton,
                policy::POLICY_LEVEL_MANDATORY,
                policy::POLICY_SCOPE_USER,
+               policy::POLICY_SOURCE_CLOUD,
                new base::FundamentalValue(true),
                NULL);
   UpdateChromePolicy(policies);