on_initialize return weight consumed and default cost to default DispatchInfo instead of zero (#5382)

* frame update

* doc

* move offchain worker trait also

* fix weigh merge

* indentation

* reorder for better git diff

* comment

* fix benchmark

* remove test

substrate/frame/treasury/src/lib.rs

@@ -98,7 +98,7 @@ use frame_support::traits::{
 use sp_runtime::{Permill, ModuleId, Percent, RuntimeDebug, traits::{
 	Zero, EnsureOrigin, StaticLookup, AccountIdConversion, Saturating, Hash, BadOrigin
 }};
-use frame_support::{weights::SimpleDispatchInfo, traits::Contains};
+use frame_support::{weights::{Weight, WeighData, SimpleDispatchInfo}, traits::Contains};
 use codec::{Encode, Decode};
 use frame_system::{self as system, ensure_signed, ensure_root};
 
@@ -553,11 +553,13 @@ decl_module! {
 			Self::payout_tip(tip);
 		}
 
-		fn on_initialize(n: T::BlockNumber) {
+		fn on_initialize(n: T::BlockNumber) -> Weight {
 			// Check to see if we should spend some funds!
 			if (n % T::SpendPeriod::get()).is_zero() {
 				Self::spend_funds();
 			}
+
+			SimpleDispatchInfo::default().weigh_data(())
 		}
 	}
 }