[Sync] Introduce ModelTypeStore interface

In this change:
- Add empty ModelTypeStore interface
- Pass WeakPtr to store into ModelTypeProcessorImpl::ctor.

BUG=517663
R=stanisc@chromium.org

Review URL: https://codereview.chromium.org/1311363009

Cr-Commit-Position: refs/heads/master@{#348255}

10 files changed, 76 insertions, 18 deletions

diff --git a/components/sync_driver/non_blocking_data_type_controller_unittest.cc b/components/sync_driver/non_blocking_data_type_controller_unittest.cc
index c0e0ecb..ef31daa 100644
--- a/components/sync_driver/non_blocking_data_type_controller_unittest.cc
+++ b/components/sync_driver/non_blocking_data_type_controller_unittest.cc
@@ -120,7 +120,8 @@ class MockSyncContextProxy : public syncer_v2::SyncContextProxy {
 class NonBlockingDataTypeControllerTest : public testing::Test {
  public:
   NonBlockingDataTypeControllerTest()
-      : type_processor_(syncer::DICTIONARY),
+      : type_processor_(syncer::DICTIONARY,
+                        base::WeakPtr<syncer_v2::ModelTypeStore>()),
         model_thread_(new base::TestSimpleTaskRunner()),
         sync_thread_(new base::TestSimpleTaskRunner()),
         controller_(syncer::DICTIONARY, true),
diff --git a/sync/BUILD.gn b/sync/BUILD.gn
index 2bc56fd..34b57b7 100644
--- a/sync/BUILD.gn
+++ b/sync/BUILD.gn
@@ -25,6 +25,8 @@ source_set("sync_core") {
     "api/attachments/attachment_store.h",
     "api/attachments/attachment_store_backend.cc",
     "api/attachments/attachment_store_backend.h",
+    "api/model_type_store.cc",
+    "api/model_type_store.h",
     "api/string_ordinal.h",
     "api/sync_change.cc",
     "api/sync_change.h",
diff --git a/sync/api/model_type_store.cc b/sync/api/model_type_store.cc
new file mode 100644
index 0000000..2555ddc
--- /dev/null
+++ b/sync/api/model_type_store.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_store.h"
+
+namespace syncer_v2 {
+
+ModelTypeStore::ModelTypeStore() {}
+
+ModelTypeStore::~ModelTypeStore() {}
+
+}  // namespace sync_v2
diff --git a/sync/api/model_type_store.h b/sync/api/model_type_store.h
new file mode 100644
index 0000000..817238e
--- /dev/null
+++ b/sync/api/model_type_store.h
@@ -0,0 +1,20 @@
+// 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_STORE_H_
+#define SYNC_API_MODEL_TYPE_STORE_H_
+
+namespace syncer_v2 {
+
+// Interface for store used by ModelTypeProcessor for persisting sync related
+// data (entity state and data type state).
+class ModelTypeStore {
+ public:
+  ModelTypeStore();
+  virtual ~ModelTypeStore();
+};
+
+}  // namespace syncer_v2
+
+#endif  // SYNC_API_MODEL_TYPE_STORE_H_
diff --git a/sync/engine/model_type_processor_impl.cc b/sync/engine/model_type_processor_impl.cc
index 3afd428..55aa73b 100644
--- a/sync/engine/model_type_processor_impl.cc
+++ b/sync/engine/model_type_processor_impl.cc
@@ -13,10 +13,13 @@
 
 namespace syncer_v2 {
 
-ModelTypeProcessorImpl::ModelTypeProcessorImpl(syncer::ModelType type)
+ModelTypeProcessorImpl::ModelTypeProcessorImpl(
+    syncer::ModelType type,
+    base::WeakPtr<ModelTypeStore> store)
     : type_(type),
       is_preferred_(false),
       is_connected_(false),
+      store_(store),
       weak_ptr_factory_for_ui_(this),
       weak_ptr_factory_for_sync_(this) {}
 
diff --git a/sync/engine/model_type_processor_impl.h b/sync/engine/model_type_processor_impl.h
index fb626e8..04a3141 100644
--- a/sync/engine/model_type_processor_impl.h
+++ b/sync/engine/model_type_processor_impl.h
@@ -18,6 +18,7 @@
 namespace syncer_v2 {
 class CommitQueue;
 class ModelTypeEntity;
+class ModelTypeStore;
 class SyncContextProxy;
 
 // A sync component embedded on the synced type's thread that helps to handle
@@ -25,7 +26,8 @@ class SyncContextProxy;
 class SYNC_EXPORT_PRIVATE ModelTypeProcessorImpl : public ModelTypeProcessor,
                                                    base::NonThreadSafe {
  public:
-  ModelTypeProcessorImpl(syncer::ModelType type);
+  ModelTypeProcessorImpl(syncer::ModelType type,
+                         base::WeakPtr<ModelTypeStore> store);
   ~ModelTypeProcessorImpl() override;
 
   // Returns true if this object believes that sync is preferred for this type.
@@ -141,6 +143,11 @@ class SYNC_EXPORT_PRIVATE ModelTypeProcessorImpl : public ModelTypeProcessor,
   // them across restarts, and keep them in sync with our progress markers.
   UpdateMap pending_updates_map_;
 
+  // Store is supplied by model type implementation. ModelTypeProcessorImpl
+  // uses store for persisting sync related data (entity state and data type
+  // state).
+  base::WeakPtr<ModelTypeStore> store_;
+
   // We use two different WeakPtrFactories because we want the pointers they
   // issue to have different lifetimes.  When asked to disconnect from the sync
   // thread, we want to make sure that no tasks generated as part of the
diff --git a/sync/engine/model_type_processor_impl_unittest.cc b/sync/engine/model_type_processor_impl_unittest.cc
index c1b6b88..8f57d69 100644
--- a/sync/engine/model_type_processor_impl_unittest.cc
+++ b/sync/engine/model_type_processor_impl_unittest.cc
@@ -135,7 +135,9 @@ ModelTypeProcessorImplTest::ModelTypeProcessorImplTest()
     : mock_queue_(new MockCommitQueue()),
       injectable_sync_context_proxy_(
           new InjectableSyncContextProxy(mock_queue_)),
-      type_processor_(new ModelTypeProcessorImpl(kModelType)) {}
+      type_processor_(
+          new ModelTypeProcessorImpl(kModelType,
+                                     base::WeakPtr<ModelTypeStore>())) {}
 
 ModelTypeProcessorImplTest::~ModelTypeProcessorImplTest() {
 }
diff --git a/sync/internal_api/sync_context_proxy_impl_unittest.cc b/sync/internal_api/sync_context_proxy_impl_unittest.cc
index 00fe80c..f4981d7 100644
--- a/sync/internal_api/sync_context_proxy_impl_unittest.cc
+++ b/sync/internal_api/sync_context_proxy_impl_unittest.cc
@@ -58,7 +58,8 @@ class SyncContextProxyImplTest : public ::testing::Test {
 
 // Try to connect a type to a SyncContext that has already shut down.
 TEST_F(SyncContextProxyImplTest, FailToConnect1) {
-  ModelTypeProcessorImpl themes_sync_proxy(syncer::THEMES);
+  ModelTypeProcessorImpl themes_sync_proxy(syncer::THEMES,
+                                           base::WeakPtr<ModelTypeStore>());
   DisableSync();
   themes_sync_proxy.Enable(GetProxy());
 
@@ -69,7 +70,8 @@ TEST_F(SyncContextProxyImplTest, FailToConnect1) {
 
 // Try to connect a type to a SyncContext as it shuts down.
 TEST_F(SyncContextProxyImplTest, FailToConnect2) {
-  ModelTypeProcessorImpl themes_sync_proxy(syncer::THEMES);
+  ModelTypeProcessorImpl themes_sync_proxy(syncer::THEMES,
+                                           base::WeakPtr<ModelTypeStore>());
   themes_sync_proxy.Enable(GetProxy());
   DisableSync();
 
@@ -81,7 +83,8 @@ TEST_F(SyncContextProxyImplTest, FailToConnect2) {
 // Tests the case where the type's sync proxy shuts down first.
 TEST_F(SyncContextProxyImplTest, TypeDisconnectsFirst) {
   scoped_ptr<ModelTypeProcessorImpl> themes_sync_proxy(
-      new ModelTypeProcessorImpl(syncer::THEMES));
+      new ModelTypeProcessorImpl(syncer::THEMES,
+                                 base::WeakPtr<ModelTypeStore>()));
   themes_sync_proxy->Enable(GetProxy());
 
   base::RunLoop run_loop_;
@@ -94,7 +97,8 @@ TEST_F(SyncContextProxyImplTest, TypeDisconnectsFirst) {
 // Tests the case where the sync thread shuts down first.
 TEST_F(SyncContextProxyImplTest, SyncDisconnectsFirst) {
   scoped_ptr<ModelTypeProcessorImpl> themes_sync_proxy(
-      new ModelTypeProcessorImpl(syncer::THEMES));
+      new ModelTypeProcessorImpl(syncer::THEMES,
+                                 base::WeakPtr<ModelTypeStore>()));
   themes_sync_proxy->Enable(GetProxy());
 
   base::RunLoop run_loop_;
diff --git a/sync/sessions/model_type_registry_unittest.cc b/sync/sessions/model_type_registry_unittest.cc
index 648a6a8..9ab1d29 100644
--- a/sync/sessions/model_type_registry_unittest.cc
+++ b/sync/sessions/model_type_registry_unittest.cc
@@ -17,8 +17,6 @@
 
 namespace syncer {
 
-using syncer_v2::ModelTypeProcessorImpl;
-
 class ModelTypeRegistryTest : public ::testing::Test {
  public:
   ModelTypeRegistryTest();
@@ -145,8 +143,10 @@ TEST_F(ModelTypeRegistryTest, SetEnabledDirectoryTypes_OffAndOn) {
 }
 
 TEST_F(ModelTypeRegistryTest, NonBlockingTypes) {
-  ModelTypeProcessorImpl themes_sync_proxy(syncer::THEMES);
-  ModelTypeProcessorImpl sessions_sync_proxy(syncer::SESSIONS);
+  syncer_v2::ModelTypeProcessorImpl themes_sync_proxy(
+      syncer::THEMES, base::WeakPtr<syncer_v2::ModelTypeStore>());
+  syncer_v2::ModelTypeProcessorImpl sessions_sync_proxy(
+      syncer::SESSIONS, base::WeakPtr<syncer_v2::ModelTypeStore>());
   scoped_refptr<base::DeferredSequencedTaskRunner> task_runner =
       new base::DeferredSequencedTaskRunner(
           base::ThreadTaskRunnerHandle::Get());
@@ -176,8 +176,10 @@ TEST_F(ModelTypeRegistryTest, NonBlockingTypes) {
 }
 
 TEST_F(ModelTypeRegistryTest, NonBlockingTypesWithDirectoryTypes) {
-  ModelTypeProcessorImpl themes_sync_proxy(syncer::THEMES);
-  ModelTypeProcessorImpl sessions_sync_proxy(syncer::SESSIONS);
+  syncer_v2::ModelTypeProcessorImpl themes_sync_proxy(
+      syncer::THEMES, base::WeakPtr<syncer_v2::ModelTypeStore>());
+  syncer_v2::ModelTypeProcessorImpl sessions_sync_proxy(
+      syncer::SESSIONS, base::WeakPtr<syncer_v2::ModelTypeStore>());
   scoped_refptr<base::DeferredSequencedTaskRunner> task_runner =
       new base::DeferredSequencedTaskRunner(
           base::ThreadTaskRunnerHandle::Get());
@@ -224,10 +226,12 @@ TEST_F(ModelTypeRegistryTest, NonBlockingTypesWithDirectoryTypes) {
 }
 
 TEST_F(ModelTypeRegistryTest, DeletionOrdering) {
-  scoped_ptr<ModelTypeProcessorImpl> themes_sync_proxy(
-      new ModelTypeProcessorImpl(syncer::THEMES));
-  scoped_ptr<ModelTypeProcessorImpl> sessions_sync_proxy(
-      new ModelTypeProcessorImpl(syncer::SESSIONS));
+  scoped_ptr<syncer_v2::ModelTypeProcessorImpl> themes_sync_proxy(
+      new syncer_v2::ModelTypeProcessorImpl(
+          syncer::THEMES, base::WeakPtr<syncer_v2::ModelTypeStore>()));
+  scoped_ptr<syncer_v2::ModelTypeProcessorImpl> sessions_sync_proxy(
+      new syncer_v2::ModelTypeProcessorImpl(
+          syncer::SESSIONS, base::WeakPtr<syncer_v2::ModelTypeStore>()));
   scoped_refptr<base::DeferredSequencedTaskRunner> task_runner =
       new base::DeferredSequencedTaskRunner(
           base::ThreadTaskRunnerHandle::Get());
diff --git a/sync/sync.gyp b/sync/sync.gyp
index 37eb375..177c332 100644
--- a/sync/sync.gyp
+++ b/sync/sync.gyp
@@ -76,6 +76,8 @@
         'api/attachments/attachment_store.h',
         'api/attachments/attachment_store_backend.cc',
         'api/attachments/attachment_store_backend.h',
+        'api/model_type_store.cc',
+        'api/model_type_store.h',
         'api/string_ordinal.h',
         'api/sync_change.cc',
         'api/sync_change.h',