Revert of [Sync] Erase sync DB when corrupted

sync/BUILD.gn

 # Copyright 2014 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.
 
 import("//build/config/features.gni")
 import("//testing/test.gni")
 
 component("sync") {
   public_deps = [
     ":sync_core",
@@ skipping 426 matching lines @@
 static_library("test_support_sync_core") {
   testonly = true
   sources = [
     "internal_api/public/base/model_type_test_util.cc",
     "internal_api/public/base/model_type_test_util.h",
     "js/js_test_util.cc",
     "js/js_test_util.h",
     "sessions/test_util.cc",
     "sessions/test_util.h",
     "test/callback_counter.h",
-    "test/directory_backing_store_corruption_testing.cc",
-    "test/directory_backing_store_corruption_testing.h",
     "test/engine/fake_model_worker.cc",
     "test/engine/fake_model_worker.h",
     "test/engine/fake_sync_scheduler.cc",
     "test/engine/fake_sync_scheduler.h",
     "test/engine/injectable_sync_context_proxy.cc",
     "test/engine/injectable_sync_context_proxy.h",
     "test/engine/mock_connection_manager.cc",
     "test/engine/mock_connection_manager.h",
     "test/engine/mock_model_type_sync_proxy.cc",
     "test/engine/mock_model_type_sync_proxy.h",
@@ skipping 24 matching lines @@
     "test/null_transaction_observer.h",
     "test/sessions/mock_debug_info_getter.cc",
     "test/sessions/mock_debug_info_getter.h",
     "test/sessions/test_scoped_session_event_listener.h",
     "test/test_directory_backing_store.cc",
     "test/test_directory_backing_store.h",
     "test/test_transaction_observer.cc",
     "test/test_transaction_observer.h",
     "test/trackable_mock_invalidation.cc",
     "test/trackable_mock_invalidation.h",
-    "util/mock_unrecoverable_error_handler.cc",
-    "util/mock_unrecoverable_error_handler.h",
     "util/test_unrecoverable_error_handler.cc",
     "util/test_unrecoverable_error_handler.h",
   ]
 
   public_deps = [
     "//base",
     "//testing/gmock",
     "//testing/gtest",
     "//sync",
   ]
@@ skipping 322 matching lines @@
       ":fake_server_jni",
       ":sync_core",
       ":test_support_sync_fake_server",
       "//base",
       "//sync/protocol:protocol",
       "//testing/gtest",
       "//url:url",
     ]
   }
 }