Introduce a layering in the invalidation component as public and impl

components/invalidation/unacked_invalidation_set_test_util.h

Index: components/invalidation/unacked_invalidation_set_test_util.h
diff --git a/components/invalidation/unacked_invalidation_set_test_util.h b/components/invalidation/unacked_invalidation_set_test_util.h
deleted file mode 100644
index 4adbb56c6f4e068e4d51cf0a39992d304b433712..0000000000000000000000000000000000000000
--- a/components/invalidation/unacked_invalidation_set_test_util.h
+++ /dev/null
@@ -1,30 +0,0 @@
-// 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 COMPONENTS_INVALIDATION_UNACKED_INVALIDATION_SET_TEST_UTIL_H_
-#define COMPONENTS_INVALIDATION_UNACKED_INVALIDATION_SET_TEST_UTIL_H_
-
-#include "components/invalidation/unacked_invalidation_set.h"
-
-#include "testing/gmock/include/gmock/gmock-matchers.h"
-
-namespace syncer {
-
-namespace test_util {
-
-void PrintTo(const UnackedInvalidationSet& invalidations, ::std::ostream* os);
-
-void PrintTo(const UnackedInvalidationsMap& map, ::std::ostream* os);
-
-::testing::Matcher<const UnackedInvalidationSet&> Eq(
-    const UnackedInvalidationSet& expected);
-
-::testing::Matcher<const UnackedInvalidationsMap&> Eq(
-    const UnackedInvalidationsMap& expected);
-
-}  // namespace test_util
-
-}  // namespace syncer
-
-#endif  // COMPONENTS_INVALIDATION_UNACKED_INVALIDATION_SET_TEST_UTIL_H_