mash: Allow a subset of D-Bus clients to be created in DBusThreadManager

chrome/browser/chromeos/dbus_thread_manager_chrome.cc

+// Copyright 2016 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/browser/chromeos/dbus_thread_manager_chrome.h"
+
+#include <utility>
+
+#include "chromeos/dbus/dbus_thread_manager.h"
+
+namespace {
+
+DBusThreadManagerChrome* g_instance = nullptr;
+
+}  // namespace
+
+// static
+DBusThreadManagerChrome* DBusThreadManagerChrome::Get() {
+  CHECK(g_instance);
+  return g_instance;
+}
+
+DBusThreadManagerChrome::DBusThreadManagerChrome() {
+  DCHECK(!g_instance);
+  g_instance = this;
+  DCHECK(chromeos::DBusThreadManager::Get());
+}
+
+DBusThreadManagerChrome::~DBusThreadManagerChrome() {
+  DCHECK_EQ(this, g_instance);
+  g_instance = nullptr;
+}
+
+//JAMES for now, just forward. In theory, chrome should own this one. But it's
+// used in content/browser/tracing and extensions/browser/api/diagnostics
+chromeos::DebugDaemonClient* DBusThreadManagerChrome::GetDebugDaemonClient() {
+  return chromeos::DBusThreadManager::Get()->GetDebugDaemonClient();
+}
+
+chromeos::SystemClockClient* DBusThreadManagerChrome::GetSystemClockClient() {
+  return chromeos::DBusThreadManager::Get()->GetSystemClockClient();
+}