Remove Http2String wrapper for std::string.

gfe-relnote: n/a, no functional change.
PiperOrigin-RevId: 263816460
Change-Id: I4f365540414e6a3d78fd00ce6b39a4cdd4c14140
diff --git a/http2/hpack/decoder/hpack_decoder_string_buffer.h b/http2/hpack/decoder/hpack_decoder_string_buffer.h
index 8a810b2..d8dce6c 100644
--- a/http2/hpack/decoder/hpack_decoder_string_buffer.h
+++ b/http2/hpack/decoder/hpack_decoder_string_buffer.h
@@ -12,10 +12,10 @@
 #include <stddef.h>
 
 #include <ostream>
+#include <string>
 
 #include "net/third_party/quiche/src/http2/hpack/huffman/hpack_huffman_decoder.h"
 #include "net/third_party/quiche/src/http2/platform/api/http2_export.h"
-#include "net/third_party/quiche/src/http2/platform/api/http2_string.h"
 #include "net/third_party/quiche/src/http2/platform/api/http2_string_piece.h"
 
 namespace http2 {
@@ -58,7 +58,7 @@
   // unless the string has been buffered (to avoid forcing a potentially
   // unnecessary copy). ReleaseString() also resets the instance so that it can
   // be used to collect another string.
-  Http2String ReleaseString();
+  std::string ReleaseString();
 
   State state_for_testing() const { return state_; }
   Backing backing_for_testing() const { return backing_; }
@@ -70,7 +70,7 @@
  private:
   // Storage for the string being buffered, if buffering is necessary
   // (e.g. if Huffman encoded, buffer_ is storage for the decoded string).
-  Http2String buffer_;
+  std::string buffer_;
 
   // The Http2StringPiece to be returned by HpackDecoderStringBuffer::str(). If
   // a string has been collected, but not buffered, value_ points to that