Remove duplicated code from sync related unit tests.

sync/api/sync_change_processor_delegator.h

Index: sync/api/sync_change_processor_delegator.h
diff --git a/sync/api/sync_change_processor_delegator.h b/sync/api/sync_change_processor_delegator.h
new file mode 100644
index 0000000000000000000000000000000000000000..d0cf876f52133de149789ae5a1367496a3cf0087
--- /dev/null
+++ b/sync/api/sync_change_processor_delegator.h
@@ -0,0 +1,37 @@
+// 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.
+
+#ifndef SYNC_API_SYNC_CHANGE_PROCESSOR_DELEGATOR_H_
+#define SYNC_API_SYNC_CHANGE_PROCESSOR_DELEGATOR_H_
+
+#include "sync/api/sync_change_processor.h"
+
+namespace syncer {
+
+// A delegator for use in unit tests.

[tim (not reviewing), 2014/02/06 19:26:47]

Let's put Test in the name of this class somehow to distinguish it from
production use.  Also, I think Wrapper or Proxy (WrapperForTest, ProxyForTest,
TestWrapper, TestProxy) are better names than delegator. 

[maniscalco, 2014/02/06 20:05:27]

Good idea.  Renamed to SyncChangeProcessorWrapperForTest. Done.

+class SyncChangeProcessorDelegator : public SyncChangeProcessor {
+ public:
+  // Create a SyncChangeProcessorDelegator.
+  //
+  // All method calls are forwarded to |recipient|. Caller maintains ownership
+  // of |recipient| and is responsible for ensuring it outlives this object.
+  SyncChangeProcessorDelegator(syncer::SyncChangeProcessor* recipient);

[tim (not reviewing), 2014/02/06 19:26:47]

single arg constructors should be explicit.

[maniscalco, 2014/02/06 20:05:27]

Done.

+  virtual ~SyncChangeProcessorDelegator();
+
+  // SyncChangeProcessor implementation.
+  virtual syncer::SyncError ProcessSyncChanges(
+      const tracked_objects::Location& from_here,
+      const syncer::SyncChangeList& change_list) OVERRIDE;
+  virtual syncer::SyncDataList GetAllSyncData(syncer::ModelType type)
+      const OVERRIDE;
+
+ private:
+  syncer::SyncChangeProcessor* const recipient_;

[tim (not reviewing), 2014/02/06 19:26:47]

nit - wrapped_ might be a better name.

[maniscalco, 2014/02/06 20:05:27]

Done.

+
+  DISALLOW_COPY_AND_ASSIGN(SyncChangeProcessorDelegator);
+};
+
+}  // namespace syncer
+
+#endif  // SYNC_API_SYNC_CHANGE_PROCESSOR_DELEGATOR_H_