Re-introduce printers for Node, Position, PositionAnchorType in GTest

Source/core/testing/CoreTestHelpers.h

Index: Source/core/testing/CoreTestHelpers.h
diff --git a/Source/core/testing/CoreTestHelpers.h b/Source/core/testing/CoreTestHelpers.h
deleted file mode 100644
index f21607546c3a3f2f695f138a713be54da849679c..0000000000000000000000000000000000000000
--- a/Source/core/testing/CoreTestHelpers.h
+++ /dev/null
@@ -1,22 +0,0 @@
-// Copyright 2015 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 CoreTestHelpers_h
-#define CoreTestHelpers_h
-
-#include "core/editing/Position.h"
-
-namespace blink {
-
-class Node;
-
-std::ostream& operator<<(std::ostream&, const Node&);
-std::ostream& operator<<(std::ostream&, const Node*);
-std::ostream& operator<<(std::ostream&, PositionAnchorType);
-std::ostream& operator<<(std::ostream&, const Position&);
-std::ostream& operator<<(std::ostream&, const PositionInComposedTree&);
-
-} // namespace blink
-
-#endif // CoreTestHelpers_h