Take absl::string_view by value instead of const-ref in ParseDictionary

As all the other parsing functions do.

PiperOrigin-RevId: 484576083

quiche/common/structured_headers.cc

diff --git a/quiche/common/structured_headers.cc b/quiche/common/structured_headers.cc
index 958f627..1f8a12f 100644
--- a/quiche/common/structured_headers.cc
+++ b/quiche/common/structured_headers.cc
@@ -875,7 +875,7 @@
   return absl::nullopt;
 }
 
-absl::optional<Dictionary> ParseDictionary(const absl::string_view& str) {
+absl::optional<Dictionary> ParseDictionary(absl::string_view str) {
   StructuredHeaderParser parser(str, StructuredHeaderParser::kFinal);
   absl::optional<Dictionary> dictionary = parser.ReadDictionary();
   if (dictionary && parser.FinishParsing()) return dictionary;

quiche/common/structured_headers.h

diff --git a/quiche/common/structured_headers.h b/quiche/common/structured_headers.h
index c9f2795..00bf795 100644
--- a/quiche/common/structured_headers.h
+++ b/quiche/common/structured_headers.h
@@ -309,8 +309,7 @@
 // Returns the result of parsing the header value as a general Dictionary, if it
 // can be parsed as one, or nullopt if it cannot. Structured-Headers Draft 15
 // only.
-QUICHE_EXPORT absl::optional<Dictionary> ParseDictionary(
-    const absl::string_view& str);
+QUICHE_EXPORT absl::optional<Dictionary> ParseDictionary(absl::string_view str);
 
 // Serialization is implemented for Structured-Headers Draft 15 only.
 QUICHE_EXPORT absl::optional<std::string> SerializeItem(const Item& value);