Uses SpdyStringPiece instead of std::string in an expectation, as required by Chromium.

gfe-relnote: n/a (test only)
PiperOrigin-RevId: 285217337
Change-Id: Id328074fd68e0487aa49c5de745c27b2820cfc66

spdy/core/hpack/hpack_encoder_test.cc

diff --git a/spdy/core/hpack/hpack_encoder_test.cc b/spdy/core/hpack/hpack_encoder_test.cc
index 67b1ac6..b905214 100644
--- a/spdy/core/hpack/hpack_encoder_test.cc
+++ b/spdy/core/hpack/hpack_encoder_test.cc
@@ -277,7 +277,7 @@
                   Pair("cookie", "val2"), Pair("cookie", "val3"),
                   Pair("accept", "text/html, text/plain,application/xml"),
                   Pair("cookie", "val4"),
-                  Pair("withnul", std::string("one\0two", 7))));
+                  Pair("withnul", SpdyStringPiece("one\0two", 7))));
 }
 
 class HpackEncoderTest : public HpackEncoderTestBase,