Allow sync to resume in local backend mode after it has been disabled.

components/browser_sync/profile_sync_service_unittest.cc

Index: components/browser_sync/profile_sync_service_unittest.cc
diff --git a/components/browser_sync/profile_sync_service_unittest.cc b/components/browser_sync/profile_sync_service_unittest.cc
index fc0d17f4356cdd56abf2c413b5ee55c6d9f30ac4..4dd3cb85a24675b73f3981bd21573c7723b0f22f 100644
--- a/components/browser_sync/profile_sync_service_unittest.cc
+++ b/components/browser_sync/profile_sync_service_unittest.cc
@@ -386,7 +386,6 @@ TEST_F(ProfileSyncServiceTest, SuccessfulInitialization) {
 TEST_F(ProfileSyncServiceTest, SuccessfulLocalBackendInitialization) {
   prefs()->SetManagedPref(syncer::prefs::kSyncManaged,
                           base::MakeUnique<base::Value>(false));
-  IssueTestTokens();
   CreateServiceWithLocalSyncBackend();
   ExpectDataTypeManagerCreation(1, GetDefaultConfigureCalledCallback());
   ExpectSyncEngineCreation(1);
@@ -943,6 +942,34 @@ TEST_F(ProfileSyncServiceTest, DisableSyncOnClient) {
   EXPECT_FALSE(service()->GetLocalDeviceInfoProvider()->GetLocalDeviceInfo());
 }
 
+// Verify a that local sync mode resumes after the policy is lifted.
+TEST_F(ProfileSyncServiceTest, LocalBackendDisabledByPolicy) {
+  prefs()->SetManagedPref(syncer::prefs::kSyncManaged,
+                          base::MakeUnique<base::Value>(false));
+  CreateServiceWithLocalSyncBackend();
+  ExpectDataTypeManagerCreation(1, GetDefaultConfigureCalledCallback());
+  ExpectSyncEngineCreation(1);
+  InitializeForNthSync();
+  EXPECT_FALSE(service()->IsManaged());
+  EXPECT_TRUE(service()->IsSyncActive());
+
+  prefs()->SetManagedPref(syncer::prefs::kSyncManaged,
+                          base::MakeUnique<base::Value>(true));
+
+  EXPECT_TRUE(service()->IsManaged());
+  EXPECT_FALSE(service()->IsSyncActive());
+
+  prefs()->SetManagedPref(syncer::prefs::kSyncManaged,
+                          base::MakeUnique<base::Value>(false));
+
+  ExpectDataTypeManagerCreation(1, GetDefaultConfigureCalledCallback());
+  ExpectSyncEngineCreation(1);
+
+  service()->RequestStart();
+  EXPECT_FALSE(service()->IsManaged());
+  EXPECT_TRUE(service()->IsSyncActive());
+}
+
 // Regression test for crbug/555434. The issue is that check for sessions DTC in
 // OnSessionRestoreComplete was creating map entry with nullptr which later was
 // dereferenced in OnSyncCycleCompleted. The fix is to use find() to check if