sync: Support non-blocking initial sync in proto

sync/sessions/data_type_tracker.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_SESSIONS_DATA_TYPE_TRACKER_H_
 #define SYNC_SESSIONS_DATA_TYPE_TRACKER_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 21 matching lines @@
 
   // Tracks that a local change has been made to this type.
   void RecordLocalChange();
 
   // Tracks that a local refresh request has been made for this type.
   void RecordLocalRefreshRequest();
 
   // Tracks that we received invalidation notifications for this type.
   void RecordRemoteInvalidation(scoped_ptr<InvalidationInterface> incoming);
 
+  // Takes note that initial sync is pending for this type.
+  void RecordInitialSyncRequired();
+
   // Records that a sync cycle has been performed successfully.
   // Generally, this means that all local changes have been committed and all
   // remote changes have been downloaded, so we can clear any flags related to
   // pending work.
   void RecordSuccessfulSyncCycle();
 
   // Updates the size of the invalidations payload buffer.
   void UpdatePayloadBufferSize(size_t new_size);
 
   // Returns true if there is a good reason to perform a sync cycle.  This does
   // not take into account whether or not now is a good time to perform a sync
   // cycle.  That's for the scheduler to decide.
   bool IsSyncRequired() const;
 
   // Returns true if there is a good reason to fetch updates for this type as
   // part of the next sync cycle.
   bool IsGetUpdatesRequired() const;
 
   // Returns true if there is an uncommitted local change.
   bool HasLocalChangePending() const;
 
   // Returns true if we've received an invalidation since we last fetched
   // updates.
   bool HasPendingInvalidation() const;
 
   // Returns true if an explicit refresh request is still outstanding.
   bool HasRefreshRequestPending() const;
 
+  // Returns true if this type is requesting an initial sync.
+  bool IsInitialSyncRequired() const;
+
   // Fills in the legacy invalidaiton payload information fields.
   void SetLegacyNotificationHint(
       sync_pb::DataTypeProgressMarker* progress) const;
 
   // Fills some type-specific contents of a GetUpdates request protobuf.  These
   // messages provide the server with the information it needs to decide how to
   // handle a request.
   void FillGetUpdatesTriggersMessage(sync_pb::GetUpdateTriggers* msg) const;
 
   // Returns true if the type is currently throttled.
@@ skipping 21 matching lines @@
 
   // The list of invalidations received since the last successful sync cycle.
   // This list may be incomplete.  See also:
   // drop_tracker_.IsRecoveringFromDropEvent() and server_payload_overflow_.
   //
   // This list takes ownership of its contents.
   ScopedVector<InvalidationInterface> pending_invalidations_;
 
   size_t payload_buffer_size_;
 
+  // Set to true if this type is ready for, but has not yet completed initial
+  // sync.
+  bool initial_sync_required_;
+
   // If !unthrottle_time_.is_null(), this type is throttled and may not download
   // or commit data until the specified time.
   base::TimeTicks unthrottle_time_;
 
   // A helper to keep track invalidations we dropped due to overflow.
   scoped_ptr<InvalidationInterface> last_dropped_invalidation_;
 
   DISALLOW_COPY_AND_ASSIGN(DataTypeTracker);
 };
 
 }  // namespace sessions
 }  // namespace syncer
 
 #endif  // SYNC_SESSIONS_DATA_TYPE_TRACKER_H_