Add MinidumpContextWriter test

minidump/minidump_context_test_util.h

Index: minidump/minidump_context_test_util.h
diff --git a/minidump/minidump_context_test_util.h b/minidump/minidump_context_test_util.h
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+// 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.
+
+#ifndef CRASHPAD_MINIDUMP_MINIDUMP_CONTEXT_TEST_UTIL_H_
+#define CRASHPAD_MINIDUMP_MINIDUMP_CONTEXT_TEST_UTIL_H_
+
+#include <stdint.h>
+
+#include "minidump/minidump_context.h"
+
+namespace crashpad {
+namespace test {
+
+//! \brief Initializes a context structure for testing.
+//!
+//! \param[out] context The structure to initialize.
+//! \param[in] seed The seed value. Initializing two context structures of the
+//!     same type with identical seed values should produce identical context
+//!     structures. Initialization with a different seed value should produce
+//!     a different context structure. If \a seed is `0`, \a context is zeroed
+//!     out entirely except for the flags field, which will identify the context
+//!     type. If \a seed is nonzero \a context will be populated entirely with
+//!     nonzero values.
+//!
+//! \{
+void InitializeMinidumpContextX86(MinidumpContextX86* context, uint32_t seed);
+void InitializeMinidumpContextAMD64(MinidumpContextAMD64* context,
+                                    uint32_t seed);
+//! \}
+
+//! \brief Verifies, via gtest assertions, that a context structure contains
+//!     expected values.
+//!
+//! \param[in] expect_seed The seed value used to initialize a context
+//!     structure. This is the seed value used with
+//!     InitializeMinidumpContext*().
+//! \param[in] observed The context structure to check. All fields of this
+//!     structure will be compared against the expected context structure, one
+//!     initialized with \a expect_seed.
+//! \{
+void ExpectMinidumpContextX86(uint32_t expect_seed,
+                              const MinidumpContextX86* observed);
+void ExpectMinidumpContextAMD64(uint32_t expect_seed,
+                                const MinidumpContextAMD64* observed);
+//! \}
+
+}  // namespace test
+}  // namespace crashpad
+
+#endif  // CRASHPAD_MINIDUMP_MINIDUMP_CONTEXT_TEST_UTIL_H_