[Sync] Refactor AttachmentStore classes. Introduce concept of referrer.

components/sync_driver/generic_change_processor_unittest.cc

Index: components/sync_driver/generic_change_processor_unittest.cc
diff --git a/components/sync_driver/generic_change_processor_unittest.cc b/components/sync_driver/generic_change_processor_unittest.cc
index cb0a4fc93c8662fae2dfd6256bab45be4509c832..8d305001c2edbd28a27456cb83770e826c3734b0 100644
--- a/components/sync_driver/generic_change_processor_unittest.cc
+++ b/components/sync_driver/generic_change_processor_unittest.cc
@@ -37,8 +37,7 @@ namespace {
 // A mock that keeps track of attachments passed to UploadAttachments.
 class MockAttachmentService : public syncer::AttachmentServiceImpl {
  public:
-  MockAttachmentService(
-      const scoped_refptr<syncer::AttachmentStore>& attachment_store);
+  MockAttachmentService(scoped_ptr<syncer::AttachmentStore> attachment_store);
   ~MockAttachmentService() override;
   void UploadAttachments(
       const syncer::AttachmentIdSet& attachment_ids) override;
@@ -49,8 +48,8 @@ class MockAttachmentService : public syncer::AttachmentServiceImpl {
 };
 
 MockAttachmentService::MockAttachmentService(
-    const scoped_refptr<syncer::AttachmentStore>& attachment_store)
-    : AttachmentServiceImpl(attachment_store,
+    scoped_ptr<syncer::AttachmentStore> attachment_store)
+    : AttachmentServiceImpl(attachment_store.Pass(),
                             scoped_ptr<syncer::AttachmentUploader>(
                                 new syncer::FakeAttachmentUploader),
                             scoped_ptr<syncer::AttachmentDownloader>(
@@ -78,9 +77,7 @@ MockAttachmentService::attachment_id_sets() {
 // pass MockAttachmentService to it.
 class MockSyncApiComponentFactory : public SyncApiComponentFactory {
  public:
-  MockSyncApiComponentFactory(
-      scoped_ptr<syncer::AttachmentService> attachment_service)
-      : attachment_service_(attachment_service.Pass()) {}
+  MockSyncApiComponentFactory() {}
 
   base::WeakPtr<syncer::SyncableService> GetSyncableServiceForType(
       syncer::ModelType type) override {
@@ -90,17 +87,27 @@ class MockSyncApiComponentFactory : public SyncApiComponentFactory {
   }
 
   scoped_ptr<syncer::AttachmentService> CreateAttachmentService(
-      const scoped_refptr<syncer::AttachmentStore>& attachment_store,
+      scoped_ptr<syncer::AttachmentStore> attachment_store,
       const syncer::UserShare& user_share,
       const std::string& store_birthday,
       syncer::ModelType model_type,
       syncer::AttachmentService::Delegate* delegate) override {
-    EXPECT_TRUE(attachment_service_ != NULL);
-    return attachment_service_.Pass();
+    scoped_ptr<MockAttachmentService> attachment_service(
+        new MockAttachmentService(attachment_store.Pass()));
+    // GenericChangeProcessor takes ownership of the AttachmentService, but we
+    // need to have a pointer to it so we can see that it was used properly.
+    // Take a pointer and trust that GenericChangeProcessor does not prematurely
+    // destroy it.
+    mock_attachment_service_ = attachment_service.get();
+    return attachment_service.Pass();
+  }
+
+  MockAttachmentService* GetMockAttachmentService() {
+    return mock_attachment_service_;
   }
 
  private:
-  scoped_ptr<syncer::AttachmentService> attachment_service_;
+  MockAttachmentService* mock_attachment_service_;
 };
 
 class SyncGenericChangeProcessorTest : public testing::Test {
@@ -149,25 +156,15 @@ class SyncGenericChangeProcessorTest : public testing::Test {
   }
 
   void ConstructGenericChangeProcessor(syncer::ModelType type) {
-    scoped_refptr<syncer::AttachmentStore> attachment_store =
+    MockSyncApiComponentFactory sync_factory;
+    scoped_ptr<syncer::AttachmentStore> attachment_store =
         syncer::AttachmentStore::CreateInMemoryStore();
-    scoped_ptr<MockAttachmentService> mock_attachment_service(
-        new MockAttachmentService(attachment_store));
-    // GenericChangeProcessor takes ownership of the AttachmentService, but we
-    // need to have a pointer to it so we can see that it was used properly.
-    // Take a pointer and trust that GenericChangeProcessor does not prematurely
-    // destroy it.
-    mock_attachment_service_ = mock_attachment_service.get();
-    sync_factory_.reset(
-        new MockSyncApiComponentFactory(mock_attachment_service.Pass()));
-    change_processor_.reset(
-        new GenericChangeProcessor(type,
-                                   &data_type_error_handler_,
-                                   syncable_service_ptr_factory_.GetWeakPtr(),
-                                   merge_result_ptr_factory_->GetWeakPtr(),
-                                   test_user_share_->user_share(),
-                                   sync_factory_.get(),
-                                   attachment_store));
+    change_processor_.reset(new GenericChangeProcessor(
+        type, &data_type_error_handler_,
+        syncable_service_ptr_factory_.GetWeakPtr(),
+        merge_result_ptr_factory_->GetWeakPtr(), test_user_share_->user_share(),
+        &sync_factory, attachment_store.Pass()));
+    mock_attachment_service_ = sync_factory.GetMockAttachmentService();
   }
 
   void BuildChildNodes(syncer::ModelType type, int n) {
@@ -211,7 +208,6 @@ class SyncGenericChangeProcessorTest : public testing::Test {
   DataTypeErrorHandlerMock data_type_error_handler_;
   scoped_ptr<syncer::TestUserShare> test_user_share_;
   MockAttachmentService* mock_attachment_service_;
-  scoped_ptr<SyncApiComponentFactory> sync_factory_;
 
   scoped_ptr<GenericChangeProcessor> change_processor_;
 };