[infra] Translate _sources.gypi files to _sources.gni files

runtime/lib/vmservice_sources.gni

Index: runtime/lib/vmservice_sources.gni
diff --git a/runtime/lib/vmservice_sources.gypi b/runtime/lib/vmservice_sources.gni
similarity index 64%
rename from runtime/lib/vmservice_sources.gypi
rename to runtime/lib/vmservice_sources.gni
index 55d70fa6a219d765ff0e9757f7af1412bdcf728e..a5e1131fbf7ec4e724396e8ae190b4f16149d151 100644
--- a/runtime/lib/vmservice_sources.gypi
+++ b/runtime/lib/vmservice_sources.gni
@@ -1,11 +1,6 @@
-# Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
+# Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 # Sources that patch the library "dart:_vmservice".
-
-{
-  'sources': [
-    'vmservice.cc',
-  ],
-}
+vmservice_runtime_sources = [ "vmservice.cc" ]