Add MinidumpThreadWriter, MinidumpThreadListWriter, and their test

minidump/minidump_memory_writer_test_util.h

Index: minidump/minidump_memory_writer_test_util.h
diff --git a/minidump/minidump_memory_writer_test_util.h b/minidump/minidump_memory_writer_test_util.h
index f6ad22927791c200085be8893b3adf7505057992..69b2aebbb36673bb29b5b8de89023cbdbe25c03e 100644
--- a/minidump/minidump_memory_writer_test_util.h
+++ b/minidump/minidump_memory_writer_test_util.h
@@ -56,9 +56,7 @@ class TestMinidumpMemoryWriter final : public MinidumpMemoryWriter {
 };
 
 //! \brief Verifies, via gtest assertions, that a MINIDUMP_MEMORY_DESCRIPTOR
-//!     structure contains expected values, and that the memory region it points
-//!     to contains expected values assuming it was written by a
-//!     TestMinidumpMemoryWriter object.
+//!     structure contains expected values.
 //!
 //! In \a expected and \a observed,
 //! MINIDUMP_MEMORY_DESCRIPTOR::StartOfMemoryRange and
@@ -70,6 +68,21 @@ class TestMinidumpMemoryWriter final : public MinidumpMemoryWriter {
 //!     expected values.
 //! \param[in] observed A MINIDUMP_MEMORY_DESCRIPTOR structure containing
 //!     observed values.
+void ExpectMinidumpMemoryDescriptor(const MINIDUMP_MEMORY_DESCRIPTOR* expected,
+                                    const MINIDUMP_MEMORY_DESCRIPTOR* observed);
+
+//! \brief Verifies, via gtest assertions, that a MINIDUMP_MEMORY_DESCRIPTOR
+//!     structure contains expected values, and that the memory region it points
+//!     to contains expected values assuming it was written by a
+//!     TestMinidumpMemoryWriter object.
+//!
+//! \a expected and \a observed are compared by
+//! ExpectMinidumpMemoryDescriptor().
+//!
+//! \param[in] expected A MINIDUMP_MEMORY_DESCRIPTOR structure containing
+//!     expected values.
+//! \param[in] observed A MINIDUMP_MEMORY_DESCRIPTOR structure containing
+//!     observed values.
 //! \param[in] file_contents The contents of the minidump file in which \a
 //!     observed was found. The memory region referenced by \a observed will be
 //!     read from this string.