sync: Refactor migration integration tests

chrome/browser/sync/test/integration/migration_watcher.h

+// Copyright 2014 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 CHROME_BROWSER_SYNC_TEST_INTEGRATION_MIGRATION_WATCHER_H_
+#define CHROME_BROWSER_SYNC_TEST_INTEGRATION_MIGRATION_WATCHER_H_
+
+#include "base/macros.h"
+#include "chrome/browser/sync/backend_migrator.h"
+#include "sync/internal_api/public/base/model_type.h"
+
+class ProfileSyncServiceHarness;
+class MigrationWaiter;
+
+// Helper class to observe and record migration state.
+class MigrationWatcher : public browser_sync::MigrationObserver {
+ public:
+  explicit MigrationWatcher(ProfileSyncServiceHarness* harness);
+  virtual ~MigrationWatcher();
+
+  // Returns true if the observed profile has a migration in progress.
+  bool HasPendingBackendMigration() const;
+
+  // Returns the set of types this class has observed being migrated.
+  syncer::ModelTypeSet GetMigratedTypes() const;
+
+  // Implementation of browser_sync::MigrationObserver.
+  virtual void OnMigrationStateChange() OVERRIDE;
+
+  // Registers the |waiter| to receive callbacks on migration state change.
+  void set_migration_waiter(MigrationWaiter* waiter);
+
+  // Unregisters the current MigrationWaiter, if any.
+  void clear_migration_waiter();
+
+ private:
+  // The ProfileSyncServiceHarness to watch.
+  ProfileSyncServiceHarness* const harness_;
+
+  // The set of data types currently undergoing migration.
+  syncer::ModelTypeSet pending_types_;
+
+  // The set of data types for which migration is complete. Accumulated by
+  // successive calls to OnMigrationStateChanged.
+  syncer::ModelTypeSet migrated_types_;
+
+  // The MigrationWatier that is waiting for this migration to complete.
+  MigrationWaiter* migration_waiter_;
+
+  DISALLOW_COPY_AND_ASSIGN(MigrationWatcher);
+};
+
+#endif  // CHROME_BROWSER_SYNC_TEST_INTEGRATION_MIGRATION_WATCHER_H_