Make HardwareChromeOS own debugd.

It only exists in Chrome OS, Brillo doesn't have it.

Test: ./update_engine_unittests
Bug: 28800946

Change-Id: I49d2024dbad5e0bf78bbc479f97dabb569b32c56
diff --git a/hardware_chromeos.h b/hardware_chromeos.h
index bc0e891..03ad750 100644
--- a/hardware_chromeos.h
+++ b/hardware_chromeos.h
@@ -22,6 +22,7 @@
 
 #include <base/macros.h>
 #include <base/time/time.h>
+#include <debugd/dbus-proxies.h>
 
 #include "update_engine/common/hardware_interface.h"
 
@@ -39,6 +40,7 @@
   // HardwareInterface methods.
   bool IsOfficialBuild() const override;
   bool IsNormalBootMode() const override;
+  bool AreDevFeaturesEnabled() const override;
   bool IsOOBEEnabled() const override;
   bool IsOOBEComplete(base::Time* out_time_of_oobe) const override;
   std::string GetHardwareClass() const override;
@@ -60,6 +62,8 @@
 
   bool is_oobe_enabled_;
 
+  std::unique_ptr<org::chromium::debugdProxyInterface> debugd_proxy_;
+
   DISALLOW_COPY_AND_ASSIGN(HardwareChromeOS);
 };