Move minidump/*_test_util.* to minidump/test

minidump/minidump_string_writer_test_util.h

-// Copyright 2014 The Crashpad Authors. All rights reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#include <dbghelp.h>
-
-#include <string>
-
-#include "util/file/string_file_writer.h"
-
-namespace crashpad {
-namespace test {
-
-//! \brief Returns the contents of a MinidumpUTF8String.
-//!
-//! If \a rva points outside of the range of \a file_writer, or if any of the
-//! string data would lie outside of the range of \a file_writer, this function
-//! will fail.
-//!
-//! \param[in] file_writer A StringFileWriter into which MinidumpWritable
-//!     objects have been written.
-//! \param[in] rva An offset in \a file_writer at which to find the desired
-//!     string.
-//!
-//! \return On success, the string read from \a file_writer at offset \a rva. On
-//!     failure, returns an empty string, with a nonfatal assertion logged to
-//!     gtest.
-std::string MinidumpUTF8StringAtRVA(const StringFileWriter& file_writer,
-                                    RVA rva);
-
-}  // namespace test
-}  // namespace crashpad