[Sync] Implement support for updating storage key for new entities

components/sync/model/entity_change.h

Index: components/sync/model/entity_change.h
diff --git a/components/sync/model/entity_change.h b/components/sync/model/entity_change.h
index 408f370d54196da122bbf7feb691ded0c8e1d48c..12b6b5c0a0945e82038a6ec99c8165f9b680ae32 100644
--- a/components/sync/model/entity_change.h
+++ b/components/sync/model/entity_change.h
@@ -28,6 +28,9 @@ class EntityChange {
   std::string storage_key() const { return storage_key_; }
   ChangeType type() const { return type_; }
   const EntityData& data() const { return data_.value(); }
+  // TODO(pavely): data_ptr() is added temporarily to support converting

[skym, 2017/05/31 19:53:11]

Can we get a tracking bug for removing this?

[pavely, 2017/06/02 18:23:45]

Done.

+  // ModelTypeSyncBridge::MergeSyncData from map to change list.
+  const EntityDataPtr& data_ptr() const { return data_; }
 
  private:
   EntityChange(const std::string& storage_key,