Use string(StringPiece) instead of StringPiece::as_string().

net/spdy/hpack/hpack_entry.cc

Index: net/spdy/hpack/hpack_entry.cc
diff --git a/net/spdy/hpack/hpack_entry.cc b/net/spdy/hpack/hpack_entry.cc
index 8c5d3d436f2c1fce835fb7b9911df5122e4ee4a2..d5c873ff26ca53dac8c3e802aed68283506cb530 100644
--- a/net/spdy/hpack/hpack_entry.cc
+++ b/net/spdy/hpack/hpack_entry.cc
@@ -77,9 +77,9 @@ size_t HpackEntry::Size() const {
 }
 
 std::string HpackEntry::GetDebugString() const {
-  return "{ name: \"" + name_ref_.as_string() + "\", value: \"" +
-         value_ref_.as_string() + "\", index: " +
-         base::SizeTToString(insertion_index_) +
+  return "{ name: \"" + std::string(name_ref_) + "\", value: \"" +
+         std::string(value_ref_) +
+         "\", index: " + base::SizeTToString(insertion_index_) +
          (IsStatic() ? " static" : (IsLookup() ? " lookup" : " dynamic")) +
          " }";
 }