mash: Store chrome --mash crash key metadata in shared memory

chrome/app/mash/mash_crash_keys_unittest.cc

+// Copyright 2017 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.
+
+#include "chrome/app/mash/mash_crash_keys.h"
+
+#include <stdint.h>
+
+#include "base/debug/crash_logging.h"
+#include "base/files/file_path.h"
+#include "base/files/file_util.h"
+#include "base/strings/stringprintf.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+TEST(MashCrashKeys, Basics) {
+  EXPECT_EQ(-1, mash_crash_keys::GetSharedMemoryFdForTesting());
+
+  mash_crash_keys::Initialize();
+
+  // Shared memory was allocated.
+  EXPECT_NE(-1, mash_crash_keys::GetSharedMemoryFdForTesting());
+  const base::FilePath expected_shm_path(
+      base::StringPrintf("/dev/shm/chrome_crash_keys_%d", getpid()));
+  EXPECT_TRUE(base::PathExists(expected_shm_path));
+  int64_t file_size;
+  EXPECT_TRUE(base::GetFileSize(expected_shm_path, &file_size));
+  // Hard-code size because the OS-level crash_reporter needs to be updated
+  // if breakpad changes the size of SimpleStringDictionary.
+  EXPECT_EQ(32768, file_size);
+
+  // Crash keys were registered and can be used.
+  base::debug::SetCrashKeyValue("url-chunk", "http://example.com");

[hashimoto, 2017/03/02 07:42:23]

Please use the constant name kActiveUrl.

+  EXPECT_EQ(1u, mash_crash_keys::GetCrashKeyCountForTesting());
+  base::debug::ClearCrashKey("url-chunk");

[hashimoto, 2017/03/02 07:42:23]

ditto.

+  EXPECT_EQ(0u, mash_crash_keys::GetCrashKeyCountForTesting());
+
+  mash_crash_keys::Shutdown();
+
+  // Shared memory was cleaned up.
+  EXPECT_EQ(-1, mash_crash_keys::GetSharedMemoryFdForTesting());
+  EXPECT_FALSE(base::PathExists(expected_shm_path));
+}