Add MGLEcho

mojo/public/platform/native/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("../../mojo_sdk.gni")
 import("../../mojo_application.gni")
 
 mojo_sdk_source_set("system") {
   sources = [
     "system_thunks.c",
@@ skipping 88 matching lines @@
     "mojo/public/c/system",
   ]
 }
 
 mojo_sdk_source_set("gpu_thunks") {
   sources = []
 }
 
 mojo_sdk_source_set("mgl_thunks") {
   sources = [
+    "mgl_echo_thunks.c",
+    "mgl_echo_thunks.h",
     "mgl_signal_sync_point_thunks.c",
     "mgl_signal_sync_point_thunks.h",
     "mgl_thunks.c",
     "mgl_thunks.h",
   ]
 
   mojo_sdk_deps = [
     "mojo/public/c/gpu:MGL",
     "mojo/public/c/gpu:MGL_signal_sync_point",
+    "mojo/public/c/gpu:MGL_echo",
   ]
 }
 
 mojo_sdk_source_set("mgl_onscreen_thunks") {
   sources = [
     "mgl_onscreen_thunks.c",
     "mgl_onscreen_thunks.h",
   ]
 
   mojo_sdk_deps = [ "mojo/public/c/gpu:MGL_onscreen" ]
@@ skipping 39 matching lines @@
 }
 
 group("tests") {
   testonly = true
 
   deps = [
     ":platform_handle_private_apptest",
     ":system_impl_private_tests",
   ]
 }