contracts: Fix OZ-N-04 Hardcoded values

packages/contracts-bedrock/.gas-snapshot

@@ -26,13 +26,13 @@ L1BlockNumberTest:test_receive() (gas: 25436)
 L1CrossDomainMessenger_Test:testCannot_L1MessengerPause() (gas: 10909)
 L1CrossDomainMessenger_Test:test_L1MessengerMessageVersion() (gas: 8366)
 L1CrossDomainMessenger_Test:test_L1MessengerPause() (gas: 31882)
-L1CrossDomainMessenger_Test:test_L1MessengerRelayMessageSucceeds() (gas: 61175)
+L1CrossDomainMessenger_Test:test_L1MessengerRelayMessageSucceeds() (gas: 61239)
 L1CrossDomainMessenger_Test:test_L1MessengerRelayMessageToSystemContract() (gas: 44859)
 L1CrossDomainMessenger_Test:test_L1MessengerRelayShouldRevertIfPaused() (gas: 41631)
 L1CrossDomainMessenger_Test:test_L1MessengerSendMessage() (gas: 172148)
 L1CrossDomainMessenger_Test:test_L1MessengerTwiceSendMessage() (gas: 1254131)
 L1CrossDomainMessenger_Test:test_L1MessengerXDomainSenderReverts() (gas: 10566)
-L1CrossDomainMessenger_Test:test_L1MessengerxDomainMessageSenderResets() (gas: 58471)
+L1CrossDomainMessenger_Test:test_L1MessengerxDomainMessageSenderResets() (gas: 58535)
 L1StandardBridge_Test:test_depositERC20() (gas: 452873)
 L1StandardBridge_Test:test_depositERC20To() (gas: 454650)
 L1StandardBridge_Test:test_depositETH() (gas: 247054)
@@ -49,13 +49,13 @@ L1StandardBridge_Test:test_receive() (gas: 391794)
 L2CrossDomainMessenger_Test:testCannot_L2MessengerPause() (gas: 10843)
 L2CrossDomainMessenger_Test:test_L2MessengerMessageVersion() (gas: 8410)
 L2CrossDomainMessenger_Test:test_L2MessengerPause() (gas: 31837)
-L2CrossDomainMessenger_Test:test_L2MessengerRelayMessageSucceeds() (gas: 57474)
+L2CrossDomainMessenger_Test:test_L2MessengerRelayMessageSucceeds() (gas: 57538)
 L2CrossDomainMessenger_Test:test_L2MessengerRelayMessageToSystemContract() (gas: 24567)
 L2CrossDomainMessenger_Test:test_L2MessengerRelayShouldRevertIfPaused() (gas: 41599)
 L2CrossDomainMessenger_Test:test_L2MessengerSendMessage() (gas: 119659)
 L2CrossDomainMessenger_Test:test_L2MessengerTwiceSendMessage() (gas: 133096)
 L2CrossDomainMessenger_Test:test_L2MessengerXDomainSenderReverts() (gas: 10588)
-L2CrossDomainMessenger_Test:test_L2MessengerxDomainMessageSenderResets() (gas: 54795)
+L2CrossDomainMessenger_Test:test_L2MessengerxDomainMessageSenderResets() (gas: 54859)
 L2OutputOracleTest:testCannot_appendCurrentTimestamp() (gas: 18627)
 L2OutputOracleTest:testCannot_appendEmptyOutput() (gas: 16756)
 L2OutputOracleTest:testCannot_appendFutureTimestamp() (gas: 18708)

packages/contracts-bedrock/contracts/L1/OptimismPortal.sol

@@ -67,6 +67,16 @@ contract OptimismPortal is ResourceMetering {
      */
     address public l2Sender = DEFAULT_L2_SENDER;
 
+    /**
+     * @notice The L2 gas limit set when eth is deposited using the receive() function.
+     */
+    uint64 internal constant RECEIVE_DEFAULT_GAS_LIMIT = 100_000;
+
+    /**
+     * @notice Additional gas reserved for clean up after finalizing a transaction withdrawal.
+     */
+    uint256 internal constant FINALIZE_GAS_BUFFER = 20_000;
+
     /**
      * @notice A list of withdrawal hashes which have been successfully finalized.
      */
@@ -87,7 +97,7 @@ contract OptimismPortal is ResourceMetering {
      *         function for EOAs. Contracts should call the depositTransaction() function directly.
      */
     receive() external payable {
-        depositTransaction(msg.sender, msg.value, 100000, false, bytes(""));
+        depositTransaction(msg.sender, msg.value, RECEIVE_DEFAULT_GAS_LIMIT, false, bytes(""));
     }
 
     /**
@@ -221,7 +231,7 @@ contract OptimismPortal is ResourceMetering {
         // target contract is at least the gas limit specified by the user. We can do this by
         // enforcing that, at this point in time, we still have gaslimit + buffer gas available.
         require(
-            gasleft() >= _gasLimit + 20000,
+            gasleft() >= _gasLimit + FINALIZE_GAS_BUFFER,
             "OptimismPortal: insufficient gas to finalize withdrawal"
         );
 

packages/contracts-bedrock/contracts/L2/L2ToL1MessagePasser.sol

@@ -39,6 +39,19 @@ contract L2ToL1MessagePasser {
      */
     event WithdrawerBalanceBurnt(uint256 indexed amount);
 
+    /*************
+     * Constants *
+     *************/
+
+    /**
+     * @notice The L1 gas limit set when eth is withdrawn using the receive() function.
+     */
+    uint256 internal constant RECEIVE_DEFAULT_GAS_LIMIT = 100_000;
+
+    /*************
+     * Variables *
+     *************/
+
     /**
      * @notice Includes the message hashes for all withdrawals
      */
@@ -53,7 +66,7 @@ contract L2ToL1MessagePasser {
      * @notice Allows users to withdraw ETH by sending directly to this contract.
      */
     receive() external payable {
-        initiateWithdrawal(msg.sender, 100000, bytes(""));
+        initiateWithdrawal(msg.sender, RECEIVE_DEFAULT_GAS_LIMIT, bytes(""));
     }
 
     /**

packages/contracts-bedrock/contracts/universal/CrossDomainMessenger.sol

@@ -54,7 +54,10 @@ abstract contract CrossDomainMessenger is
 
     uint32 public constant MIN_GAS_DYNAMIC_OVERHEAD = 1;
 
-    uint32 public constant MIN_GAS_CONSTANT_OVERHEAD = 100000;
+    uint32 public constant MIN_GAS_CONSTANT_OVERHEAD = 100_000;
+
+    uint256 internal constant RELAY_GAS_REQUIRED = 45_000;
+    uint256 internal constant RELAY_GAS_BUFFER = RELAY_GAS_REQUIRED - 5000;
 
     /*************
      * Variables *
@@ -209,12 +212,15 @@ abstract contract CrossDomainMessenger is
         require(successfulMessages[versionedHash] == false, "Message has already been relayed.");
 
         // TODO: Make sure this will always give us enough gas.
-        require(gasleft() >= _minGasLimit + 45000, "Insufficient gas to relay message.");
+        require(
+            gasleft() >= _minGasLimit + RELAY_GAS_REQUIRED,
+            "Insufficient gas to relay message."
+        );
 
         xDomainMsgSender = _sender;
         (bool success, ) = ExcessivelySafeCall.excessivelySafeCall(
             _target,
-            gasleft() - 40000,
+            gasleft() - RELAY_GAS_BUFFER,
             _value,
             0,
             _message

packages/contracts-bedrock/contracts/universal/StandardBridge.sol

@@ -68,6 +68,15 @@ abstract contract StandardBridge {
         bytes _data
     );
 
+    /*************
+     * Constants *
+     *************/
+
+    /**
+     * @notice The L2 gas limit set when eth is depoisited using the receive() function.
+     */
+    uint32 internal constant RECEIVE_DEFAULT_GAS_LIMIT = 200_000;
+
     /*************
      * Variables *
      *************/
@@ -129,7 +138,7 @@ abstract contract StandardBridge {
      * to L2 through the standard bridge.
      */
     receive() external payable onlyEOA {
-        _initiateBridgeETH(msg.sender, msg.sender, msg.value, 200_000, bytes(""));
+        _initiateBridgeETH(msg.sender, msg.sender, msg.value, RECEIVE_DEFAULT_GAS_LIMIT, bytes(""));
     }
 
     /**