Some reorganizing to respond to code review comments
diff --git a/config.m4 b/config.m4
index af3624c..a6ce55e 100644
--- a/config.m4
+++ b/config.m4
@@ -249,6 +249,7 @@
     src/core/ext/transport/chttp2/transport/frame_settings.cc \
     src/core/ext/transport/chttp2/transport/frame_window_update.cc \
     src/core/ext/transport/chttp2/transport/hpack_encoder.cc \
+    src/core/ext/transport/chttp2/transport/hpack_mapping.cc \
     src/core/ext/transport/chttp2/transport/hpack_parser.cc \
     src/core/ext/transport/chttp2/transport/hpack_table.cc \
     src/core/ext/transport/chttp2/transport/http2_settings.cc \