Revert "[Sync] Actively guard against provider being cleared in DeviceInfoSyncBridge."

components/sync/device_info/device_info_sync_bridge_unittest.cc

Index: components/sync/device_info/device_info_sync_bridge_unittest.cc
diff --git a/components/sync/device_info/device_info_sync_bridge_unittest.cc b/components/sync/device_info/device_info_sync_bridge_unittest.cc
index 983873672985d587b1dcf67e0831b791a8b6e6b2..583553a2ad252938c87ceeef9ee59372b6b4f99b 100644
--- a/components/sync/device_info/device_info_sync_bridge_unittest.cc
+++ b/components/sync/device_info/device_info_sync_bridge_unittest.cc
@@ -26,7 +26,6 @@
 
 namespace syncer {
 
-using base::OneShotTimer;
 using base::Time;
 using base::TimeDelta;
 using sync_pb::DeviceInfoSpecifics;
@@ -263,8 +262,6 @@ class DeviceInfoSyncBridgeTest : public testing::Test,
     return processor_;
   }
 
-  const OneShotTimer& pulse_timer() { return bridge()->pulse_timer_; }
-
   // Should only be called after the bridge has been initialized. Will first
   // recover the bridge's store, so another can be initialized later, and then
   // deletes the bridge.
@@ -353,16 +350,6 @@ TEST_F(DeviceInfoSyncBridgeTest, LocalProviderInitRace) {
   EXPECT_TRUE(processor()->metadata());
 }
 
-// Simulate shutting down sync during the ModelTypeStore callbacks. The pulse
-// timer should still be initialized, even though reconcile never occurs.
-TEST_F(DeviceInfoSyncBridgeTest, ClearProviderDuringInit) {
-  InitializeBridge();
-  local_device()->Clear();
-  base::RunLoop().RunUntilIdle();
-  EXPECT_EQ(0u, bridge()->GetAllDeviceInfo().size());
-  EXPECT_TRUE(pulse_timer().IsRunning());
-}
-
 TEST_F(DeviceInfoSyncBridgeTest, GetClientTagNormal) {
   InitializeBridge();
   const std::string guid = "abc";
@@ -578,25 +565,6 @@ TEST_F(DeviceInfoSyncBridgeTest, ApplyDeleteNonexistent) {
   EXPECT_EQ(1, change_count());
 }
 
-TEST_F(DeviceInfoSyncBridgeTest, ClearProviderAndApply) {
-  // This will initialize the provider a first time.
-  InitializeAndPump();
-  EXPECT_EQ(1u, bridge()->GetAllDeviceInfo().size());
-
-  const DeviceInfoSpecifics specifics = CreateSpecifics(1, Time::Now());
-
-  local_device()->Clear();
-  SyncError error = bridge()->ApplySyncChanges(
-      bridge()->CreateMetadataChangeList(), EntityAddList({specifics}));
-  EXPECT_FALSE(error.IsSet());
-  EXPECT_EQ(1u, bridge()->GetAllDeviceInfo().size());
-
-  local_device()->Initialize(CreateModel(kDefaultLocalSuffix));
-  error = bridge()->ApplySyncChanges(bridge()->CreateMetadataChangeList(),
-                                     EntityAddList({specifics}));
-  EXPECT_EQ(2u, bridge()->GetAllDeviceInfo().size());
-}
-
 TEST_F(DeviceInfoSyncBridgeTest, MergeEmpty) {
   InitializeAndPump();
   EXPECT_EQ(1, change_count());
@@ -710,24 +678,6 @@ TEST_F(DeviceInfoSyncBridgeTest, MergeLocalGuidBeforeReconcile) {
   EXPECT_EQ(0u, bridge()->GetAllDeviceInfo().size());
 }
 
-TEST_F(DeviceInfoSyncBridgeTest, ClearProviderAndMerge) {
-  // This will initialize the provider a first time.
-  InitializeAndPump();
-  EXPECT_EQ(1u, bridge()->GetAllDeviceInfo().size());
-
-  const DeviceInfoSpecifics specifics = CreateSpecifics(1, Time::Now());
-
-  local_device()->Clear();
-  SyncError error = bridge()->MergeSyncData(
-      bridge()->CreateMetadataChangeList(), InlineEntityDataMap({specifics}));
-  EXPECT_FALSE(error.IsSet());
-  EXPECT_EQ(1u, bridge()->GetAllDeviceInfo().size());
-  local_device()->Initialize(CreateModel(kDefaultLocalSuffix));
-  error = bridge()->MergeSyncData(bridge()->CreateMetadataChangeList(),
-                                  InlineEntityDataMap({specifics}));
-  EXPECT_EQ(2u, bridge()->GetAllDeviceInfo().size());
-}
-
 TEST_F(DeviceInfoSyncBridgeTest, CountActiveDevices) {
   InitializeAndPump();
   EXPECT_EQ(1, bridge()->CountActiveDevices());