Add Device::SetCommandHandler

BUG:24267885
Change-Id: Ibcc1af050ad0de4130dfc3349545f6ab1ddc3f49
Reviewed-on: https://weave-review.googlesource.com/1250
Reviewed-by: Vitaly Buka <vitalybuka@google.com>
diff --git a/libweave/src/device_manager.cc b/libweave/src/device_manager.cc
index 6ff3a88..009df46 100644
--- a/libweave/src/device_manager.cc
+++ b/libweave/src/device_manager.cc
@@ -106,8 +106,9 @@
   return command_manager_->FindCommand(id);
 }
 
-void DeviceManager::AddCommandAddedCallback(const CommandCallback& callback) {
-  return command_manager_->AddCommandAddedCallback(callback);
+void DeviceManager::AddCommandHandler(const std::string& command_name,
+                                      const CommandHandlerCallback& callback) {
+  return command_manager_->AddCommandHandler(command_name, callback);
 }
 
 bool DeviceManager::SetStateProperties(