sync: Change progress marker checking in tests

chrome/browser/sync/test/integration/updated_progress_marker_checker.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_UPDATED_PROGRESS_MARKER_CHECKER_H_
+#define CHROME_BROWSER_SYNC_TEST_INTEGRATION_UPDATED_PROGRESS_MARKER_CHECKER_H_
+
+#include "chrome/browser/sync/test/integration/single_client_status_change_checker.h"
+
+// Waits until the latest progress markers are available.
+//
+// There are several limitations to this checker:
+// - It assumes that this client is the only one committing at this time.
+// - It relies on the test-only 'self-notify' to trigger an extra GetUpdate
+//   cycle after every commit.
+// - It's flaky.  In some rare cases, the IsExitConditionSatisifed() call could
+//   return a false positive.  See comments in the .cc file for details.
+//
+// Because of these limitations, we intend to eventually migrate all tests off
+// of this checker.  Please do not use it in new tests.
+class UpdatedProgressMarkerChecker : public SingleClientStatusChangeChecker {
+ public:
+  explicit UpdatedProgressMarkerChecker(ProfileSyncService* service);
+  virtual ~UpdatedProgressMarkerChecker();
+
+  virtual bool IsExitConditionSatisfied() OVERRIDE;
+  virtual std::string GetDebugMessage() const OVERRIDE;
+};
+
+#endif  // CHROME_BROWSER_SYNC_TEST_INTEGRATION_UPDATED_PROGRESS_MARKER_CHECKER_H_