Added handshaker.[ch] to build.yaml.
diff --git a/grpc.gemspec b/grpc.gemspec
index 369851b..6b8beba 100755
--- a/grpc.gemspec
+++ b/grpc.gemspec
@@ -177,6 +177,7 @@
   s.files += %w( src/core/lib/channel/compress_filter.h )
   s.files += %w( src/core/lib/channel/connected_channel.h )
   s.files += %w( src/core/lib/channel/context.h )
+  s.files += %w( src/core/lib/channel/handshaker.h )
   s.files += %w( src/core/lib/channel/http_client_filter.h )
   s.files += %w( src/core/lib/channel/http_server_filter.h )
   s.files += %w( src/core/lib/compression/algorithm_metadata.h )
@@ -332,6 +333,7 @@
   s.files += %w( src/core/lib/channel/channel_stack_builder.c )
   s.files += %w( src/core/lib/channel/compress_filter.c )
   s.files += %w( src/core/lib/channel/connected_channel.c )
+  s.files += %w( src/core/lib/channel/handshaker.c )
   s.files += %w( src/core/lib/channel/http_client_filter.c )
   s.files += %w( src/core/lib/channel/http_server_filter.c )
   s.files += %w( src/core/lib/compression/compression.c )