Add 'dsset' structure.

scheduler/appengine/engine/internal/tq_tasks.proto

 // Copyright 2017 The LUCI Authors.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //      http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
 syntax = "proto3";
 
 package internal.tq_tasks;
 
 // TODO(vadimsh): These will change.
 
 message TickLaterTask {
   string job_id = 1;
   int64 tick_nonce = 2;
 }
 
 
-message StartInvocationTask {
+message TriggerInvocationTask {
+  string job_id = 1;
+  int64 trigger_id = 2;
+}
+
+
+message TriageTriggersTask {
   string job_id = 1;
 }
+
+
+message LaunchInvocationsBatchTask {
+  string job_id = 1;
+  repeated int64 inv_id = 2;
+}
+
+
+message LaunchInvocationTask {
+  string job_id = 1;
+  int64 inv_id = 2;
+}