Add some v8 bindings files to GN build.

Source/bindings/modules/v8/v8.gni

Index: Source/bindings/modules/v8/v8.gni
diff --git a/Source/bindings/modules/v8/v8.gni b/Source/bindings/modules/v8/v8.gni
new file mode 100644
index 0000000000000000000000000000000000000000..3cc1024c33f4982807927a0760e5e8a093296a25
--- /dev/null
+++ b/Source/bindings/modules/v8/v8.gni
@@ -0,0 +1,22 @@
+# 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("custom/custom.gni")
+
+# Make the files absolute so they can be imported to anywhere.
+bindings_modules_v8_files = get_path_info(
+  [
+    "DictionaryHelperForModules.cpp",
+    "IDBBindingUtilities.cpp",
+    "IDBBindingUtilities.h",
+    "ModuleBindingsInitializer.cpp",
+    "ModuleBindingsInitializer.h",
+  ],
+  "abspath") + bindings_modules_v8_custom_files
+
+bindings_modules_v8_unittest_files = get_path_info(
+  [
+    "IDBBindingUtilitiesTest.cpp",
+  ],
+  "abspath")