Merge branch 'stable-2.15'

* stable-2.15:
  NoteDbMigrator: Set checkExisting(false) on PackInserter
  ChangeRebuilderImpl: Fail when new NoteDb state is null
  PrimaryStorageMigrator: Log individual migrations at debug
  Document the deprecation of old change IDs
  Update JGit to get PackInserter fix
  AbstractChangeNotes: Never open repo when NoteDb is off
  MigrateToNoteDb: Only reindex change index
  PolyGerrit: Add background-repeat to gr-main-header
  Revert "Add privateByDefault config to /config/server/info"
  Private state changed event
  WIP state changed event
  Populate ChangeAttribute with WIP and private status.
  Fix invalid json example in POST access endpoint
  Add default values in create project dialog and group config
  Update JGit to 4.9.2.201712150930-r
  gerrit_plugin: Don't add Implementation-Vendor manifest entry
  Fix schema_154 migration from version 2.13 and older
  Default to writing comments in JSON format

Change-Id: Iee55a0f00ce2430cd400c64491acde3651a0390d

java/com/google/gerrit/server/events/WorkInProgressStateChangedEvent.java

@@ -0,0 +1,28 @@
+// Copyright (C) 2017 The Android Open Source Project
+//
+// 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.
+
+package com.google.gerrit.server.events;
+
+import com.google.common.base.Supplier;
+import com.google.gerrit.reviewdb.client.Change;
+import com.google.gerrit.server.data.AccountAttribute;
+
+public class WorkInProgressStateChangedEvent extends ChangeEvent {
+  static final String TYPE = "wip-state-changed";
+  public Supplier<AccountAttribute> changer;
+
+  protected WorkInProgressStateChangedEvent(Change change) {
+    super(TYPE, change);
+  }
+}