[Sync] Add plumbing of context from client to server

sync/engine/directory_commit_contribution.h

 // 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_ENGINE_DIRECTORY_COMMIT_CONTRIBUTION_H_
 #define SYNC_ENGINE_DIRECTORY_COMMIT_CONTRIBUTION_H_
 
 #include <vector>
 
 #include "base/gtest_prod_util.h"
@@ skipping 48 matching lines @@
   // Updates this contribution's contents in accordance with the provided
   // |response|.
   //
   // This function may make model-neutral changes to the directory.  It is not
   // valid to call this function unless AddToCommitMessage() was called earlier.
   // This function should not be called more than once.
   virtual SyncerError ProcessCommitResponse(
       const sync_pb::ClientToServerResponse& response,
       sessions::StatusController* status) OVERRIDE;
 
-  // Cleans up any temproary state associated with the commit.  Must be called
+  // Cleans up any temporary state associated with the commit.  Must be called
   // before destruction.
   virtual void CleanUp() OVERRIDE;
 
   // Returns the number of entries included in this contribution.
   virtual size_t GetNumEntries() const OVERRIDE;
 
  private:
   class DirectoryCommitContributionTest;
   FRIEND_TEST_ALL_PREFIXES(DirectoryCommitContributionTest, GatherByTypes);
   FRIEND_TEST_ALL_PREFIXES(DirectoryCommitContributionTest,
                            GatherAndTruncate);
 
   DirectoryCommitContribution(
+      ModelType type,
       const std::vector<int64>& metahandles,
       const google::protobuf::RepeatedPtrField<sync_pb::SyncEntity>& entities,
       syncable::Directory* directory);
 
   void UnsetSyncingBits();
 
   syncable::Directory* dir_;
+  ModelType type_;
   const std::vector<int64> metahandles_;
   const google::protobuf::RepeatedPtrField<sync_pb::SyncEntity> entities_;
   size_t entries_start_index_;
 
   // This flag is tracks whether or not the directory entries associated with
   // this commit still have their SYNCING bits set.  These bits will be set when
   // the CommitContribution is created with Build() and unset when CleanUp() is
   // called.  This flag must be unset by the time our destructor is called.
   bool syncing_bits_set_;
 
   DISALLOW_COPY_AND_ASSIGN(DirectoryCommitContribution);
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_ENGINE_DIRECTORY_COMMIT_CONTRIBUTION_H_