chromeos: Add suspend delay tests for PowerManagerClient.

chromeos/dbus/power_manager_client.h

 // Copyright (c) 2012 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.
 
 #ifndef CHROMEOS_DBUS_POWER_MANAGER_CLIENT_H_
 #define CHROMEOS_DBUS_POWER_MANAGER_CLIENT_H_
 
 #include <string>
 
 #include "base/callback.h"
@@ skipping 180 matching lines @@
   // Returns the number of callbacks returned by GetSuspendReadinessCallback()
   // for the current suspend attempt but not yet called. Used by tests.
   virtual int GetNumPendingSuspendReadinessCallbacks() = 0;
 
   // Creates the instance.
   static PowerManagerClient* Create(DBusClientImplementationType type);
 
   ~PowerManagerClient() override;
 
  protected:
+  // Needs to call DBusClient::Init().
+  friend class PowerManagerClientTest;
+
   // Create() should be used instead.
   PowerManagerClient();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(PowerManagerClient);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_DBUS_POWER_MANAGER_CLIENT_H_