Delete unused HexDecode method. No behavior change.

net/quic/core/quic_utils.h

Index: net/quic/core/quic_utils.h
diff --git a/net/quic/core/quic_utils.h b/net/quic/core/quic_utils.h
index 9ba914f34f353e48ea1bec6b0a6b93d1ae78393c..c1603dd8127ab6d87b2e84c2e8220a208a4e6590 100644
--- a/net/quic/core/quic_utils.h
+++ b/net/quic/core/quic_utils.h
@@ -96,14 +96,13 @@ class NET_EXPORT_PRIVATE QuicUtils {
       const IPEndPoint& old_address,
       const IPEndPoint& new_address);
 
-  // This converts 'num' bytes of binary to a 2*'num'-character hexadecimal
-  // representation. Return value: 2*'num' characters of ascii std::string.
+  // This converts |length| bytes of binary to a 2*|length|-character
+  // hexadecimal representation.
+  // Return value: 2*|length| characters of ASCII std::string.
   static std::string HexEncode(const char* data, size_t length);
   static std::string HexEncode(base::StringPiece data);
 
-  // This converts 2*'num' hexadecimal characters to 'num' binary data.
-  // Return value: 'num' bytes of binary data (via the 'to' argument).
-  static std::string HexDecode(const char* data, size_t length);
+  // Converts |data| from a hexadecimal ASCII std::string to binary.
   static std::string HexDecode(base::StringPiece data);
 
   // Returns a std::string containing hex and ASCII representations of |binary|,