Mojo: Make a public test_support shared library.

mojo/public/tests/test_support.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 MOJO_PUBLIC_TESTS_TEST_SUPPORT_H_
+#define MOJO_PUBLIC_TESTS_TEST_SUPPORT_H_
+
+// Note: This header should be compilable as C.
+
+#include "mojo/public/tests/test_support_export.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+MOJO_TEST_SUPPORT_EXPORT void MojoTestSupportLogPerfResult(
+    const char* test_name,
+    double value,
+    const char* units);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // MOJO_PUBLIC_TESTS_TEST_SUPPORT_H_