sync: Add interfaces for per-type sync

sync/engine/directory_commit_contribution.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_ENGINE_SYNC_DIRECTORY_COMMIT_CONTRIBUTION_H_
-#define SYNC_ENGINE_SYNC_DIRECTORY_COMMIT_CONTRIBUTION_H_
+#ifndef SYNC_ENGINE_DIRECTORY_COMMIT_CONTRIBUTION_H_
+#define SYNC_ENGINE_DIRECTORY_COMMIT_CONTRIBUTION_H_
 
 #include <vector>
 
 #include "base/gtest_prod_util.h"
+#include "base/memory/scoped_ptr.h"
 #include "sync/base/sync_export.h"
+#include "sync/engine/commit_contribution.h"
 #include "sync/internal_api/public/base/model_type.h"
 #include "sync/internal_api/public/util/syncer_error.h"
 #include "sync/protocol/sync.pb.h"
 #include "sync/sessions/status_controller.h"
 
 namespace syncer {
 
 namespace sessions {
 class StatusController;
 }  // namespace sessions
 
 namespace syncable {
 class Directory;
 }  // namespace syncable
 
 // This class represents a set of items belonging to a particular data type that
 // have been selected from the syncable Directory and prepared for commit.
 //
 // This class handles the bookkeeping related to the commit of these items,
 // including processing the commit response message and setting and unsetting
 // the SYNCING bits.
-class SYNC_EXPORT_PRIVATE SyncDirectoryCommitContribution {
+class SYNC_EXPORT_PRIVATE DirectoryCommitContribution
+    : public CommitContribution {
  public:
   // This destructor will DCHECK if UnsetSyncingBits() has not been called yet.
-  ~SyncDirectoryCommitContribution();
+  virtual ~DirectoryCommitContribution();
 
   // Build a CommitContribution from the IS_UNSYNCED items in |dir| with the
   // given |type|.  The contribution will include at most |max_items| entries.
   //
   // This function may return NULL if this type has no items ready for and
   // requiring commit.  This function may make model neutral changes to the
   // directory.
-  static SyncDirectoryCommitContribution* Build(
+  static scoped_ptr<DirectoryCommitContribution> Build(
       syncable::Directory* dir,
       ModelType type,
       size_t max_items);
 
   // Serialize this contribution's entries to the given commit request |msg|.
   //
   // This function is not const.  It will update some state in this contribution
   // that will be used when processing the associated commit response.  This
   // function should not be called more than once.
-  void AddToCommitMessage(sync_pb::ClientToServerMessage* msg);
+  virtual void AddToCommitMessage(sync_pb::ClientToServerMessage* msg) OVERRIDE;
 
   // 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.
-  SyncerError ProcessCommitResponse(
+  virtual SyncerError ProcessCommitResponse(
       const sync_pb::ClientToServerResponse& response,
-      sessions::StatusController* status);
+      sessions::StatusController* status) OVERRIDE;
 
   // Cleans up any temproary state associated with the commit.  Must be called
   // before destruction.
-  void CleanUp();
+  virtual void CleanUp() OVERRIDE;
 
   // Returns the number of entries included in this contribution.
-  size_t GetNumEntries() const;
+  virtual size_t GetNumEntries() const OVERRIDE;
 
  private:
-  class SyncDirectoryCommitContributionTest;
-  FRIEND_TEST_ALL_PREFIXES(SyncDirectoryCommitContributionTest, GatherByTypes);
-  FRIEND_TEST_ALL_PREFIXES(SyncDirectoryCommitContributionTest,
+  class DirectoryCommitContributionTest;
+  FRIEND_TEST_ALL_PREFIXES(DirectoryCommitContributionTest, GatherByTypes);
+  FRIEND_TEST_ALL_PREFIXES(DirectoryCommitContributionTest,
                            GatherAndTruncate);
 
-  SyncDirectoryCommitContribution(
+  DirectoryCommitContribution(
       const std::vector<int64>& metahandles,
       const google::protobuf::RepeatedPtrField<sync_pb::SyncEntity>& entities,
       syncable::Directory* directory);
 
   void UnsetSyncingBits();
 
   syncable::Directory* dir_;
   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(SyncDirectoryCommitContribution);
+  DISALLOW_COPY_AND_ASSIGN(DirectoryCommitContribution);
 };
 
 }  // namespace syncer
 
-#endif  // SYNC_ENGINE_SYNC_DIRECTORY_COMMIT_CONTRIBUTION_H_
+#endif  // SYNC_ENGINE_DIRECTORY_COMMIT_CONTRIBUTION_H_