Handshaker plugin mechanism.
diff --git a/gRPC-Core.podspec b/gRPC-Core.podspec
index 9d878d5..e56eedd 100644
--- a/gRPC-Core.podspec
+++ b/gRPC-Core.podspec
@@ -256,6 +256,8 @@
                       'src/core/lib/channel/context.h',
                       'src/core/lib/channel/deadline_filter.h',
                       'src/core/lib/channel/handshaker.h',
+                      'src/core/lib/channel/handshaker_factory.h',
+                      'src/core/lib/channel/handshaker_registry.h',
                       'src/core/lib/channel/http_client_filter.h',
                       'src/core/lib/channel/http_server_filter.h',
                       'src/core/lib/channel/message_size_filter.h',
@@ -436,6 +438,8 @@
                       'src/core/lib/channel/connected_channel.c',
                       'src/core/lib/channel/deadline_filter.c',
                       'src/core/lib/channel/handshaker.c',
+                      'src/core/lib/channel/handshaker_factory.c',
+                      'src/core/lib/channel/handshaker_registry.c',
                       'src/core/lib/channel/http_client_filter.c',
                       'src/core/lib/channel/http_server_filter.c',
                       'src/core/lib/channel/message_size_filter.c',
@@ -664,6 +668,8 @@
                               'src/core/lib/channel/context.h',
                               'src/core/lib/channel/deadline_filter.h',
                               'src/core/lib/channel/handshaker.h',
+                              'src/core/lib/channel/handshaker_factory.h',
+                              'src/core/lib/channel/handshaker_registry.h',
                               'src/core/lib/channel/http_client_filter.h',
                               'src/core/lib/channel/http_server_filter.h',
                               'src/core/lib/channel/message_size_filter.h',