token-server: Add protos for new API for generating service account tokens.

tokenserver/appengine/impl/services/minter/tokenminter/service.go

 // Copyright 2016 The LUCI Authors. All rights reserved.
 // Use of this source code is governed under the Apache License, Version 2.0
 // that can be found in the LICENSE file.
 
 // Package tokenminter implements TokenMinter API.
 //
 // This is main public API of The Token Server.
 package tokenminter
 
 import (
         "github.com/luci/luci-go/appengine/gaeauth/server/gaesigner"
 
         "github.com/luci/luci-go/tokenserver/appengine/impl/certchecker"
         "github.com/luci/luci-go/tokenserver/appengine/impl/delegation"
         "github.com/luci/luci-go/tokenserver/appengine/impl/machinetoken"
+        "github.com/luci/luci-go/tokenserver/appengine/impl/serviceaccounts"
 
         "github.com/luci/luci-go/tokenserver/api/minter/v1"
 )
 
 // Server implements minter.TokenMinterServer RPC interface.
 //
 // This is just an assembly of individual method implementations, properly
 // configured for use in GAE prod setting.
 type serverImpl struct {
         machinetoken.MintMachineTokenRPC
         delegation.MintDelegationTokenRPC
+        serviceaccounts.MintOAuthTokenGrantRPC
+        serviceaccounts.MintOAuthTokenViaGrantRPC
 }
 
 // NewServer returns prod TokenMinterServer implementation.
 //
 // It does all authorization checks inside.
 func NewServer() minter.TokenMinterServer {
         return &serverImpl{
                 MintMachineTokenRPC: machinetoken.MintMachineTokenRPC{
                         Signer:           gaesigner.Signer{},
                         CheckCertificate: certchecker.CheckCertificate,
                         LogToken:         machinetoken.LogToken,
                 },
                 MintDelegationTokenRPC: delegation.MintDelegationTokenRPC{
                         Signer:       gaesigner.Signer{},
                         ConfigLoader: delegation.DelegationConfigLoader,
                         LogToken:     delegation.LogToken,
                 },
         }
 }