[Sync] Add empty ModelTypeService and ModelTypeChangeProcessor interf…

…aces.

BUG=536895

Review URL: https://codereview.chromium.org/1395393003

Cr-Commit-Position: refs/heads/master@{#353787}

sync/BUILD.gn

@@ -25,6 +25,10 @@ source_set("sync_core") {
     "api/attachments/attachment_store.h",
     "api/attachments/attachment_store_backend.cc",
     "api/attachments/attachment_store_backend.h",
+    "api/model_type_change_processor.cc",
+    "api/model_type_change_processor.h",
+    "api/model_type_service.cc",
+    "api/model_type_service.h",
     "api/model_type_store.cc",
     "api/model_type_store.h",
     "api/string_ordinal.h",

sync/api/model_type_change_processor.cc

@@ -0,0 +1,13 @@
+// Copyright 2015 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 "sync/api/model_type_change_processor.h"
+
+namespace syncer_v2 {
+
+ModelTypeChangeProcessor::ModelTypeChangeProcessor() {}
+
+ModelTypeChangeProcessor::~ModelTypeChangeProcessor() {}
+
+}  // namespace syncer_v2

sync/api/model_type_change_processor.h

@@ -0,0 +1,22 @@
+// Copyright 2015 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.
+
+#ifndef SYNC_API_MODEL_TYPE_CHANGE_PROCESSOR_H_
+#define SYNC_API_MODEL_TYPE_CHANGE_PROCESSOR_H_
+
+#include "sync/base/sync_export.h"
+
+namespace syncer_v2 {
+
+// Interface used by the ModelTypeService to inform sync of local
+// changes.
+class SYNC_EXPORT ModelTypeChangeProcessor {
+ public:
+  ModelTypeChangeProcessor();
+  virtual ~ModelTypeChangeProcessor();
+};
+
+}  // namespace syncer_v2
+
+#endif  // SYNC_API_MODEL_TYPE_CHANGE_PROCESSOR_H_

sync/api/model_type_service.cc

@@ -0,0 +1,13 @@
+// Copyright 2015 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 "sync/api/model_type_service.h"
+
+namespace syncer_v2 {
+
+ModelTypeService::ModelTypeService() {}
+
+ModelTypeService::~ModelTypeService() {}
+
+}  // namespace syncer_v2

sync/api/model_type_service.h

@@ -0,0 +1,23 @@
+// Copyright 2015 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.
+
+#ifndef SYNC_API_MODEL_TYPE_SERVICE_H_
+#define SYNC_API_MODEL_TYPE_SERVICE_H_
+
+#include "sync/base/sync_export.h"
+
+namespace syncer_v2 {
+
+// Interface implemented by model types to receive updates from sync via the
+// SharedModelTypeProcessor. Provides a way for sync to update the data and
+// metadata for entities, as well as the model type state.
+class SYNC_EXPORT ModelTypeService {
+ public:
+  ModelTypeService();
+  virtual ~ModelTypeService();
+};
+
+}  // namespace syncer_v2
+
+#endif  // SYNC_API_MODEL_TYPE_SERVICE_H_

sync/internal_api/public/shared_model_type_processor.h

@@ -9,6 +9,7 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/threading/non_thread_safe.h"
+#include "sync/api/model_type_change_processor.h"
 #include "sync/base/sync_export.h"
 #include "sync/internal_api/public/base/model_type.h"
 #include "sync/internal_api/public/model_type_processor.h"
@@ -23,8 +24,10 @@ class ModelTypeStore;
 
 // A sync component embedded on the synced type's thread that helps to handle
 // communication between sync and model type threads.
-class SYNC_EXPORT_PRIVATE SharedModelTypeProcessor : public ModelTypeProcessor,
-                                                     base::NonThreadSafe {
+class SYNC_EXPORT_PRIVATE SharedModelTypeProcessor
+    : public ModelTypeProcessor,
+      public ModelTypeChangeProcessor,
+      base::NonThreadSafe {
  public:
   SharedModelTypeProcessor(syncer::ModelType type,
                            base::WeakPtr<ModelTypeStore> store);

sync/sync.gyp

@@ -76,6 +76,10 @@
         'api/attachments/attachment_store.h',
         'api/attachments/attachment_store_backend.cc',
         'api/attachments/attachment_store_backend.h',
+        'api/model_type_change_processor.cc',
+        'api/model_type_change_processor.h',
+        'api/model_type_service.cc',
+        'api/model_type_service.h',
         'api/model_type_store.cc',
         'api/model_type_store.h',
         'api/string_ordinal.h',