sync: Expose sync functionality as functions

sync/sessions/data_type_tracker.cc

 // 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.
 
 #include "sync/sessions/data_type_tracker.h"
 
+#include "base/logging.h"
 #include "sync/sessions/nudge_tracker.h"
 
 namespace syncer {
 namespace sessions {
 
 DataTypeTracker::DataTypeTracker()
   : local_nudge_count_(0),
     local_refresh_request_count_(0),
     local_payload_overflow_(false),
     server_payload_overflow_(false),
@@ skipping 49 matching lines @@
 }
 
 bool DataTypeTracker::HasPendingInvalidation() const {
   return !pending_payloads_.empty();
 }
 
 std::string DataTypeTracker::GetMostRecentInvalidationPayload() const {
   return pending_payloads_.back();
 }
 
+void DataTypeTracker::SetLegacyNotificationHint(
+    sync_pb::DataTypeProgressMarker* progress) const {
+  DCHECK(!IsThrottled())
+      << "We should not make requests if the type is throttled.";
+
+  if (HasPendingInvalidation()) {
+    // The old-style source info can contain only one hint per type.  We grab
+    // the most recent, to mimic the old coalescing behaviour.
+    progress->set_notification_hint(GetMostRecentInvalidationPayload());
+  } else if (HasLocalChangePending()) {
+    // The old-style source info sent up an empty string (as opposed to
+    // nothing at all) when the type was locally nudged, but had not received
+    // any invalidations.
+    progress->set_notification_hint("");
+  }
+}
+
 void DataTypeTracker::FillGetUpdatesTriggersMessage(
     sync_pb::GetUpdateTriggers* msg) const {
   // Fill the list of payloads, if applicable.  The payloads must be ordered
   // oldest to newest, so we insert them in the same order as we've been storing
   // them internally.
   for (PayloadList::const_iterator payload_it = pending_payloads_.begin();
        payload_it != pending_payloads_.end(); ++payload_it) {
     msg->add_notification_hint(*payload_it);
   }
 
@@ skipping 25 matching lines @@
 }
 
 void DataTypeTracker::UpdateThrottleState(base::TimeTicks now) {
   if (now >= unthrottle_time_) {
     unthrottle_time_ = base::TimeTicks();
   }
 }
 
 }  // namespace sessions
 }  // namespace syncer