Implemented _accessControlBlackList trait

BUG:25768272
BUG:25777665
Change-Id: Id32475816dbd9ec24b020f4f2a68274a978729c8
Reviewed-on: https://weave-review.googlesource.com/2209
Reviewed-by: Vitaly Buka <vitalybuka@google.com>
diff --git a/src/base_api_handler.h b/src/base_api_handler.h
index 1dbbac8..6eebfca 100644
--- a/src/base_api_handler.h
+++ b/src/base_api_handler.h
@@ -33,7 +33,7 @@
   void OnConfigChanged(const Settings& settings);
 
   DeviceRegistrationInfo* device_info_;
-  Device* device_;
+  Device* device_{nullptr};
 
   base::WeakPtrFactory<BaseApiHandler> weak_ptr_factory_{this};
   DISALLOW_COPY_AND_ASSIGN(BaseApiHandler);