Add a template-specialized constructor for der::Input for constants

net/der/input.h

Index: net/der/input.h
diff --git a/net/der/input.h b/net/der/input.h
index 5814375a2e0dc032b12d5b30217a8648b563a705..6731b0c0600afd22f623141252b7e2b58d413061 100644
--- a/net/der/input.h
+++ b/net/der/input.h
@@ -41,6 +41,11 @@ class NET_EXPORT_PRIVATE Input {
   // Creates an empty Input, one from which no data can be read.
   Input();
 
+  // Creates an Input from a constant array |data|.
+  template <size_t N>
+  explicit Input(const uint8_t(&data)[N])
+      : data_(data), len_(N) {}
+
   // Creates an Input from the given |data| and |len|.
   Input(const uint8_t* data, size_t len);