32.Refactoring in preparation for SpdyHeaderBlock cleanup.

net/tools/quic/spdy_balsa_utils.cc

Index: net/tools/quic/spdy_balsa_utils.cc
diff --git a/net/tools/quic/spdy_balsa_utils.cc b/net/tools/quic/spdy_balsa_utils.cc
index e045af9225e0e2f76c320618e23fd95a05f7893d..37889a4ef9d28a2f148876619b19e590405b7fb6 100644
--- a/net/tools/quic/spdy_balsa_utils.cc
+++ b/net/tools/quic/spdy_balsa_utils.cc
@@ -271,9 +271,23 @@ SpdyHeaderBlock SpdyBalsaUtils::RequestHeadersToSpdyHeaders(
   DCHECK(!host_and_port.empty());
   DCHECK(!path.empty());
 
+  if (scheme.empty()) {
+    if (request_headers.HasHeader("Scheme")) {
+      request_headers.GetAllOfHeaderAsString("Scheme", &scheme);
+    } else {
+      // Requests must contain a :scheme header, and unless another scheme is
+      // detected, https is assumed.
+      scheme = "https";
+    }
+  }
+
   SpdyHeaderBlock block;
   PopulateHttp2RequestHeaderBlock(request_headers, scheme, host_and_port, path,
                                   &block);
+
+  // If a "Scheme" header existed in request_headers, it would have been
+  // propagated to |block|.
+  block.erase("scheme");
   return block;
 }