Add uses clauses to filegroups to ease dependency management
diff --git a/binding.gyp b/binding.gyp
index b1ae0f2..a1cdf2e 100644
--- a/binding.gyp
+++ b/binding.gyp
@@ -558,9 +558,40 @@
         'gpr',
       ],
       'sources': [
+        'src/core/ext/transport/chttp2/client/insecure/channel_create.c',
+        'src/core/ext/transport/chttp2/client/secure/secure_channel_create.c',
+        'src/core/ext/transport/chttp2/server/insecure/server_chttp2.c',
+        'src/core/ext/transport/chttp2/server/secure/server_secure_chttp2.c',
+        'src/core/ext/transport/chttp2/transport/alpn.c',
+        'src/core/ext/transport/chttp2/transport/bin_encoder.c',
+        'src/core/ext/transport/chttp2/transport/chttp2_transport.c',
+        'src/core/ext/transport/chttp2/transport/frame_data.c',
+        'src/core/ext/transport/chttp2/transport/frame_goaway.c',
+        'src/core/ext/transport/chttp2/transport/frame_ping.c',
+        'src/core/ext/transport/chttp2/transport/frame_rst_stream.c',
+        'src/core/ext/transport/chttp2/transport/frame_settings.c',
+        'src/core/ext/transport/chttp2/transport/frame_window_update.c',
+        'src/core/ext/transport/chttp2/transport/hpack_encoder.c',
+        'src/core/ext/transport/chttp2/transport/hpack_parser.c',
+        'src/core/ext/transport/chttp2/transport/hpack_table.c',
+        'src/core/ext/transport/chttp2/transport/huffsyms.c',
+        'src/core/ext/transport/chttp2/transport/incoming_metadata.c',
+        'src/core/ext/transport/chttp2/transport/parsing.c',
+        'src/core/ext/transport/chttp2/transport/status_conversion.c',
+        'src/core/ext/transport/chttp2/transport/stream_lists.c',
+        'src/core/ext/transport/chttp2/transport/stream_map.c',
+        'src/core/ext/transport/chttp2/transport/timeout_encoding.c',
+        'src/core/ext/transport/chttp2/transport/varint.c',
+        'src/core/ext/transport/chttp2/transport/writing.c',
+        'src/core/lib/census/context.c',
         'src/core/lib/census/grpc_context.c',
         'src/core/lib/census/grpc_filter.c',
         'src/core/lib/census/grpc_plugin.c',
+        'src/core/lib/census/initialize.c',
+        'src/core/lib/census/mlog.c',
+        'src/core/lib/census/operation.c',
+        'src/core/lib/census/placeholders.c',
+        'src/core/lib/census/tracing.c',
         'src/core/lib/channel/channel_args.c',
         'src/core/lib/channel/channel_stack.c',
         'src/core/lib/channel/channel_stack_builder.c',
@@ -594,6 +625,7 @@
         'src/core/lib/debug/trace.c',
         'src/core/lib/http/format_request.c',
         'src/core/lib/http/httpcli.c',
+        'src/core/lib/http/httpcli_security_connector.c',
         'src/core/lib/http/parser.c',
         'src/core/lib/iomgr/closure.c',
         'src/core/lib/iomgr/endpoint.c',
@@ -642,6 +674,20 @@
         'src/core/lib/json/json_string.c',
         'src/core/lib/json/json_writer.c',
         'src/core/lib/proto/grpc/lb/v0/load_balancer.pb.c',
+        'src/core/lib/security/b64.c',
+        'src/core/lib/security/client_auth_filter.c',
+        'src/core/lib/security/credentials.c',
+        'src/core/lib/security/credentials_metadata.c',
+        'src/core/lib/security/credentials_posix.c',
+        'src/core/lib/security/credentials_win32.c',
+        'src/core/lib/security/google_default_credentials.c',
+        'src/core/lib/security/handshake.c',
+        'src/core/lib/security/json_token.c',
+        'src/core/lib/security/jwt_verifier.c',
+        'src/core/lib/security/secure_endpoint.c',
+        'src/core/lib/security/security_connector.c',
+        'src/core/lib/security/security_context.c',
+        'src/core/lib/security/server_auth_filter.c',
         'src/core/lib/surface/alarm.c',
         'src/core/lib/surface/api_trace.c',
         'src/core/lib/surface/byte_buffer.c',
@@ -657,6 +703,7 @@
         'src/core/lib/surface/completion_queue.c',
         'src/core/lib/surface/event_string.c',
         'src/core/lib/surface/init.c',
+        'src/core/lib/surface/init_secure.c',
         'src/core/lib/surface/lame_client.c',
         'src/core/lib/surface/metadata_array.c',
         'src/core/lib/surface/server.c',
@@ -669,56 +716,9 @@
         'src/core/lib/transport/static_metadata.c',
         'src/core/lib/transport/transport.c',
         'src/core/lib/transport/transport_op_string.c',
-        'src/core/ext/transport/chttp2/transport/alpn.c',
-        'src/core/ext/transport/chttp2/transport/bin_encoder.c',
-        'src/core/ext/transport/chttp2/transport/chttp2_transport.c',
-        'src/core/ext/transport/chttp2/transport/frame_data.c',
-        'src/core/ext/transport/chttp2/transport/frame_goaway.c',
-        'src/core/ext/transport/chttp2/transport/frame_ping.c',
-        'src/core/ext/transport/chttp2/transport/frame_rst_stream.c',
-        'src/core/ext/transport/chttp2/transport/frame_settings.c',
-        'src/core/ext/transport/chttp2/transport/frame_window_update.c',
-        'src/core/ext/transport/chttp2/transport/hpack_encoder.c',
-        'src/core/ext/transport/chttp2/transport/hpack_parser.c',
-        'src/core/ext/transport/chttp2/transport/hpack_table.c',
-        'src/core/ext/transport/chttp2/transport/huffsyms.c',
-        'src/core/ext/transport/chttp2/transport/incoming_metadata.c',
-        'src/core/ext/transport/chttp2/transport/parsing.c',
-        'src/core/ext/transport/chttp2/transport/status_conversion.c',
-        'src/core/ext/transport/chttp2/transport/stream_lists.c',
-        'src/core/ext/transport/chttp2/transport/stream_map.c',
-        'src/core/ext/transport/chttp2/transport/timeout_encoding.c',
-        'src/core/ext/transport/chttp2/transport/varint.c',
-        'src/core/ext/transport/chttp2/transport/writing.c',
-        'src/core/ext/transport/chttp2/server/secure/server_secure_chttp2.c',
-        'src/core/ext/transport/chttp2/client/secure/secure_channel_create.c',
-        'src/core/ext/transport/chttp2/server/insecure/server_chttp2.c',
-        'src/core/ext/transport/chttp2/client/insecure/channel_create.c',
-        'src/core/lib/http/httpcli_security_connector.c',
-        'src/core/lib/security/b64.c',
-        'src/core/lib/security/client_auth_filter.c',
-        'src/core/lib/security/credentials.c',
-        'src/core/lib/security/credentials_metadata.c',
-        'src/core/lib/security/credentials_posix.c',
-        'src/core/lib/security/credentials_win32.c',
-        'src/core/lib/security/google_default_credentials.c',
-        'src/core/lib/security/handshake.c',
-        'src/core/lib/security/json_token.c',
-        'src/core/lib/security/jwt_verifier.c',
-        'src/core/lib/security/secure_endpoint.c',
-        'src/core/lib/security/security_connector.c',
-        'src/core/lib/security/security_context.c',
-        'src/core/lib/security/server_auth_filter.c',
-        'src/core/lib/surface/init_secure.c',
         'src/core/lib/tsi/fake_transport_security.c',
         'src/core/lib/tsi/ssl_transport_security.c',
         'src/core/lib/tsi/transport_security.c',
-        'src/core/lib/census/context.c',
-        'src/core/lib/census/initialize.c',
-        'src/core/lib/census/mlog.c',
-        'src/core/lib/census/operation.c',
-        'src/core/lib/census/placeholders.c',
-        'src/core/lib/census/tracing.c',
         'third_party/nanopb/pb_common.c',
         'third_party/nanopb/pb_decode.c',
         'third_party/nanopb/pb_encode.c',