[Sync] Add context proto and directory support

sync/syncable/directory.h

 // Copyright 2013 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_SYNCABLE_DIRECTORY_H_
 #define SYNC_SYNCABLE_DIRECTORY_H_
 
 #include <deque>
 #include <set>
 #include <string>
@@ skipping 102 matching lines @@
     int64 transaction_version[MODEL_TYPE_COUNT];
     // The store birthday we were given by the server. Contents are opaque to
     // the client.
     std::string store_birthday;
     // The next local ID that has not been used with this cache-GUID.
     int64 next_id;
     // The serialized bag of chips we were given by the server. Contents are
     // opaque to the client. This is the serialization of a message of type
     // ChipBag defined in sync.proto. It can contains NULL characters.
     std::string bag_of_chips;
+    // The per-datatype context.
+    sync_pb::DataTypeContext datatype_context[MODEL_TYPE_COUNT];
   };
 
   // What the Directory needs on initialization to create itself and its Kernel.
   // Filled by DirectoryBackingStore::Load.
   struct KernelLoadInfo {
     PersistedKernelInfo kernel_info;
     std::string cache_guid;  // Created on first initialization, never changes.
     int64 max_metahandle;    // Computed (using sql MAX aggregate) on init.
     KernelLoadInfo() : max_metahandle(0) {
     }
@@ skipping 56 matching lines @@
   size_t GetEntriesCount() const;
   void SetDownloadProgress(
       ModelType type,
       const sync_pb::DataTypeProgressMarker& value);
 
   // Gets/Increments transaction version of a model type. Must be called when
   // holding kernel mutex.
   int64 GetTransactionVersion(ModelType type) const;
   void IncrementTransactionVersion(ModelType type);
 
+  // Getter/setters for the per datatype context.
+  void GetDataTypeContext(BaseTransaction* trans,
+                          ModelType type,
+                          sync_pb::DataTypeContext* context) const;
+  void SetDataTypeContext(BaseWriteTransaction* trans,
+                          ModelType type,
+                          const sync_pb::DataTypeContext& context);
+
   ModelTypeSet InitialSyncEndedTypes();
   bool InitialSyncEndedForType(ModelType type);
   bool InitialSyncEndedForType(BaseTransaction* trans, ModelType type);
 
   const std::string& name() const { return kernel_->name; }
 
   // (Account) Store birthday is opaque to the client, so we keep it in the
   // format it is in the proto buffer in case we switch to a binary birthday
   // later.
   std::string store_birthday() const;
@@ skipping 337 matching lines @@
   // are deleted in native models as well.
   scoped_ptr<DeleteJournal> delete_journal_;
 
   DISALLOW_COPY_AND_ASSIGN(Directory);
 };
 
 }  // namespace syncable
 }  // namespace syncer
 
 #endif // SYNC_SYNCABLE_DIRECTORY_H_