[Sync] Move some things from core/ to model(_impl)/.

components/sync/model/mutable_data_batch.h

Index: components/sync/model/mutable_data_batch.h
diff --git a/components/sync/core/data_batch_impl.h b/components/sync/model/mutable_data_batch.h
similarity index 80%
rename from components/sync/core/data_batch_impl.h
rename to components/sync/model/mutable_data_batch.h
index a1405937bf60f15924d0cfe598713accbda4c62f..5016f066a60a12864074e80f46cbf45b5edb3baa 100644
--- a/components/sync/core/data_batch_impl.h
+++ b/components/sync/model/mutable_data_batch.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef COMPONENTS_SYNC_CORE_DATA_BATCH_IMPL_H_
-#define COMPONENTS_SYNC_CORE_DATA_BATCH_IMPL_H_
+#ifndef COMPONENTS_SYNC_MODEL_MUTABLE_DATA_BATCH_H_
+#define COMPONENTS_SYNC_MODEL_MUTABLE_DATA_BATCH_H_
 
 #include <stddef.h>
 
@@ -23,10 +23,10 @@ namespace syncer {
 // them until Next() is invoked, when it gives up ownerhsip. Because a vector
 // is used internally, this impl is unaware when duplcate storage_keys are used,
 // and it is the caller's job to avoid this.
-class DataBatchImpl : public DataBatch {
+class MutableDataBatch : public DataBatch {
  public:
-  DataBatchImpl();
-  ~DataBatchImpl() override;
+  MutableDataBatch();
+  ~MutableDataBatch() override;
 
   // Takes ownership of the data tied to a given key used for storage. Put
   // should be called at most once for any given storfage_key. Data will be
@@ -42,9 +42,9 @@ class DataBatchImpl : public DataBatch {
   std::vector<KeyAndData> key_data_pairs_;
   size_t read_index_ = 0;
 
-  DISALLOW_COPY_AND_ASSIGN(DataBatchImpl);
+  DISALLOW_COPY_AND_ASSIGN(MutableDataBatch);
 };
 
 }  // namespace syncer
 
-#endif  // COMPONENTS_SYNC_CORE_DATA_BATCH_IMPL_H_
+#endif  // COMPONENTS_SYNC_MODEL_MUTABLE_DATA_BATCH_H_