Make the fuchsia mojo/public repo the source of truth.

mojo/public/cpp/system/BUILD.gn

Index: mojo/public/cpp/system/BUILD.gn
diff --git a/mojo/public/cpp/system/BUILD.gn b/mojo/public/cpp/system/BUILD.gn
deleted file mode 100644
index 51a9bc9781dd1402c11e4eeefe0bdbddce0eec06..0000000000000000000000000000000000000000
--- a/mojo/public/cpp/system/BUILD.gn
+++ /dev/null
@@ -1,19 +0,0 @@
-# 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")
-
-mojo_sdk_source_set("system") {
-  sources = [
-    "buffer.h",
-    "data_pipe.h",
-    "handle.h",
-    "macros.h",
-    "message_pipe.h",
-    "time.h",
-    "wait.h",
-  ]
-
-  mojo_sdk_public_deps = [ "mojo/public/c:system" ]
-}