Import Dart bindings as of Blink r188698. This merely copies the files over and does not attach any…

sky/engine/bindings-dart/core/dart/dart-native-extensions.gypi

Index: sky/engine/bindings-dart/core/dart/dart-native-extensions.gypi
diff --git a/sky/engine/bindings-dart/core/dart/dart-native-extensions.gypi b/sky/engine/bindings-dart/core/dart/dart-native-extensions.gypi
new file mode 100644
index 0000000000000000000000000000000000000000..c8f009e8a0ec1d563f232b53910f9cb8368083a5
--- /dev/null
+++ b/sky/engine/bindings-dart/core/dart/dart-native-extensions.gypi
@@ -0,0 +1,25 @@
+{
+  'variables': {
+    # We have to nest variables inside variables so that they can be overridden
+    # through GYP_DEFINES.
+    'variables': {
+      'enable_dart_native_extensions%': 0,
+    },
+
+    'dart_dir': '../../../../../../dart',
+
+    'conditions': [
+      ['enable_dart_native_extensions==1', {
+        'additional_target_deps': [
+          # Reference Dart from a shared library which can be used outside of Dartium
+          '../bindings/core/dart/dart-native-extensions.gyp:dart_library',
+        ],
+      }, {
+        'additional_target_deps': [
+          # Link in Dart directly
+          '<(dart_dir)/runtime/dart-runtime.gyp:libdart',
+        ],
+      }],
+    ],
+  },
+}