Removes an unnecessary method from spdy::SpdySerializedFrame.

This method is not used in Chromium, and is only used in one place internally.

Protected by removes unused code, not protected.

PiperOrigin-RevId: 623603012

quiche/spdy/core/spdy_protocol.h

diff --git a/quiche/spdy/core/spdy_protocol.h b/quiche/spdy/core/spdy_protocol.h
index 09bc49e..3e9dd34 100644
--- a/quiche/spdy/core/spdy_protocol.h
+++ b/quiche/spdy/core/spdy_protocol.h
@@ -1046,8 +1046,6 @@
     return absl::string_view{frame_, size_};
   }
 
-  operator std::string() const { return std::string{frame_, size_}; }
-
   // Returns a buffer containing the contents of the frame, of which the caller
   // takes ownership, and clears this SpdySerializedFrame.
   char* ReleaseBuffer() {