Add a new bindings2/scripts directory for Dart bindings

sky/engine/bindings2/scripts/templates/callback_interface_cpp.template

+// Copyright 2014 The Dartium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// This file has been auto-generated by {{code_generator_dart}}. DO NOT MODIFY!
+
+#include "sky/engine/config.h"
+#include "{{dart_class}}.h"
+
+{% for filename in cpp_includes %}
+#include "{{filename}}"
+{% endfor %}
+
+#include "sky/engine/tonic/dart_api_scope.h"
+#include "sky/engine/tonic/dart_converter.h"
+#include "sky/engine/tonic/dart_isolate_scope.h"
+
+namespace blink {
+
+{% for method in methods if not method.custom %}
+{{method.cpp_type}} {{dart_class}}::{{method.name}}({{method.argument_declarations | join(', ')}})
+{
+    {% set return_default = 'return true'
+           if method.idl_type == 'boolean' else 'return' %}{# void #}
+    if (!callback_.IsIsolateAlive())
+        {{return_default}};
+    DartIsolateScope scope(callback_.GetIsolate());
+    DartApiScope apiScope;
+    {% if method.call_with_this_handle %}
+    // FIXME: we ignore thisValue which may or may not be correct for Dart.
+    {% endif %}
+    {% for argument in method.arguments %}
+    Dart_Handle {{argument.handle}} = {{argument.cpp_value_to_dart_value}};
+    if (Dart_IsError({{argument.handle}}))
+        {{return_default}};
+    {% endfor %}
+    {% if method.arguments %}
+    Dart_Handle arguments[] = { {{method.arguments | join(', ', attribute='handle')}} };
+    {% else %}
+    Dart_Handle *arguments = 0;
+    {% endif %}
+
+    {% set return_with = 'return'
+           if method.idl_type == 'boolean' else '' %}{# void #}
+    {{return_with}} callback_.handleEvent({{method.arguments | length}}, arguments);
+}
+
+{% endfor %}
+}  // namespace blink