sync: Refactor migration integration tests

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

+// 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.
+
+#include "chrome/browser/sync/test/integration/migration_watcher.h"
+
+#include "chrome/browser/sync/profile_sync_service.h"
+#include "chrome/browser/sync/test/integration/migration_waiter.h"
+#include "chrome/browser/sync/test/integration/profile_sync_service_harness.h"
+
+MigrationWatcher::MigrationWatcher(ProfileSyncServiceHarness* harness)
+    : harness_(harness), migration_waiter_(NULL) {
+  browser_sync::BackendMigrator* migrator =
+      harness_->service()->GetBackendMigratorForTest();
+  // PSS must have a migrator after sync is setup and initial data type
+  // configuration is complete.
+  migrator->AddMigrationObserver(this);
+}
+
+MigrationWatcher::~MigrationWatcher() {
+  DCHECK(!migration_waiter_);
+}
+
+bool MigrationWatcher::HasPendingBackendMigration() const {
+  browser_sync::BackendMigrator* migrator =
+      harness_->service()->GetBackendMigratorForTest();
+  return migrator && migrator->state() != browser_sync::BackendMigrator::IDLE;
+}
+
+syncer::ModelTypeSet MigrationWatcher::GetMigratedTypes() const {
+  return migrated_types_;
+}
+
+void MigrationWatcher::OnMigrationStateChange() {
+  if (HasPendingBackendMigration()) {
+    // A new bunch of data types are in the process of being migrated. Merge
+    // them into |pending_types_|.
+    pending_types_.PutAll(harness_->service()
+                              ->GetBackendMigratorForTest()
+                              ->GetPendingMigrationTypesForTest());
+    DVLOG(1) << harness_->profile_debug_name()
+             << ": new pending migration types "
+             << syncer::ModelTypeSetToString(pending_types_);
+  } else {
+    // Migration just finished for a bunch of data types. Merge them into
+    // |migrated_types_|.
+    migrated_types_.PutAll(pending_types_);

[Nicolas Zea, 2014/08/20 22:24:10]

Does migrated_types_  == ProtocolTypes().Difference(pending_types_)? If so, I
don't think you need pending types around as a member.

[rlarocque, 2014/08/21 00:41:20]

No, that won't work.  This MigrationWatcher can live a long time and observe
many migrations.  If we migrate bookmarks, then migrate themes separately, the
migrated_types_ should contain both themes and bookmarks.

+    pending_types_.Clear();
+    DVLOG(1) << harness_->profile_debug_name() << ": new migrated types "
+             << syncer::ModelTypeSetToString(migrated_types_);
+  }
+
+  // Manually trigger a check of the exit condition.
+  if (migration_waiter_)
+    migration_waiter_->OnMigrationStateChange();
+}
+
+void MigrationWatcher::set_migration_waiter(MigrationWaiter* waiter) {
+  DCHECK(!migration_waiter_);
+  migration_waiter_ = waiter;
+}
+
+void MigrationWatcher::clear_migration_waiter() {
+  DCHECK(migration_waiter_);
+  migration_waiter_ = NULL;
+}