gRPC migration

Change-Id: I3129ae27d7ee12a23c7046f0d877e8064f2fd7f4
diff --git a/vendor/google.golang.org/protobuf/internal/impl/pointer_unsafe.go b/vendor/google.golang.org/protobuf/internal/impl/pointer_unsafe.go
index 088aa85..9ecf23a 100644
--- a/vendor/google.golang.org/protobuf/internal/impl/pointer_unsafe.go
+++ b/vendor/google.golang.org/protobuf/internal/impl/pointer_unsafe.go
@@ -109,6 +109,7 @@
 func (p pointer) StringPtr() **string                   { return (**string)(p.p) }
 func (p pointer) StringSlice() *[]string                { return (*[]string)(p.p) }
 func (p pointer) Bytes() *[]byte                        { return (*[]byte)(p.p) }
+func (p pointer) BytesPtr() **[]byte                    { return (**[]byte)(p.p) }
 func (p pointer) BytesSlice() *[][]byte                 { return (*[][]byte)(p.p) }
 func (p pointer) WeakFields() *weakFields               { return (*weakFields)(p.p) }
 func (p pointer) Extensions() *map[int32]ExtensionField { return (*map[int32]ExtensionField)(p.p) }