fuchsia: Implement CurrentProcessInfo

base/process/process_info_fuchsia.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 "base/process/process_info.h"
+
+#include <magenta/syscalls.h>
+
+#include "base/time/time.h"
+
+namespace base {
+
+// static
+const Time CurrentProcessInfo::CreationTime() {
+#if 0  // TODO(fuchsia): This requires a newer drop of the Fuchsia SDK.
+  mx_info_thread_stats_t thread_stats;
+  if (mx_object_get_info(mx_thread_self(), MX_INFO_THREAD_STATS, &thread_stats,
+                         sizeof(thread_stats), nullptr, nullptr) != NO_ERROR) {
+    return Time();
+  }
+  Time current_time = Time::Now();
+  TimeDelta total_runtime = TimeDelta::FromMicroseconds(
+      thread_stats.total_runtime / base::Time::kNanosecondsPerMicrosecond);
+  return Time(current_time - total_runtime);
+#else
+  return Time();
+#endif
+}
+
+}  // namespace base