Plumb polkadot backend into cumulus-collator (#269)

* The problem in the nutshell

* Make it compile

* make tests pass

* Update the parachain-upgrade module

* Fix collator tests

Co-authored-by: Bastian Köcher <git@kchr.de>

primitives/Cargo.toml

@@ -11,6 +11,7 @@ sp-std = { git = "https://github.com/paritytech/substrate", default-features = f
 sp-runtime = { git = "https://github.com/paritytech/substrate", default-features = false, branch = "master" }
 sc-chain-spec = { git = "https://github.com/paritytech/substrate", optional = true, branch = "master" }
 sp-core = { git = "https://github.com/paritytech/substrate", default-features = false, branch = "master" }
+sp-trie = { git = "https://github.com/paritytech/substrate", default-features = false, branch = "master" }
 
 # Polkadot dependencies
 polkadot-parachain = { git = "https://github.com/paritytech/polkadot", default-features = false, branch = "master" }
@@ -35,4 +36,5 @@ std = [
 	"polkadot-core-primitives/std",
 	"sp-runtime/std",
 	"sp-core/std",
+	"sp-trie/std",
 ]

primitives/src/lib.rs

@@ -57,7 +57,14 @@ pub mod inherents {
 	/// The identifier for the `set_validation_data` inherent.
 	pub const VALIDATION_DATA_IDENTIFIER: InherentIdentifier = *b"valfunp0";
 	/// The type of the inherent.
-	pub type ValidationDataType = crate::ValidationData;
+	#[derive(codec::Encode, codec::Decode, sp_core::RuntimeDebug, Clone, PartialEq)]
+	pub struct ValidationDataType {
+		pub validation_data: crate::ValidationData,
+		/// A storage proof of a predefined set of keys from the relay-chain.
+		///
+		/// The set of keys is TBD
+		pub relay_chain_state: sp_trie::StorageProof,
+	}
 }
 
 /// Well known keys for values in the storage.