Mojo JS bindings: add support to generate "dual-mode" code.

mojo/public/tools/bindings/generators/js_templates/module.amd.tmpl

Index: mojo/public/tools/bindings/generators/js_templates/module.amd.tmpl
diff --git a/mojo/public/tools/bindings/generators/js_templates/module.amd.tmpl b/mojo/public/tools/bindings/generators/js_templates/module.amd.tmpl
index 8772a404d8568fd54bb6c9588c870b23fe8415b8..1cb107f6873921a80099522050d6c45cc436c55f 100644
--- a/mojo/public/tools/bindings/generators/js_templates/module.amd.tmpl
+++ b/mojo/public/tools/bindings/generators/js_templates/module.amd.tmpl
@@ -2,10 +2,15 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-{%- if use_new_js_bindings %}
+{%- if js_bindings_mode == "both" or js_bindings_mode == "new" %}
+{{"new"|set_current_mode}}
 
 'use strict';
 
+{%-   if js_bindings_mode == "both" %}
+if (mojo && mojo.internal && mojo.config) {
+{%-   endif %}
+
 (function() {
   var mojomId = '{{module.path}}';
   if (mojo.internal.isMojomLoaded(mojomId)) {
@@ -35,7 +40,18 @@
 {% include "module_definition.tmpl" %}
 })();
 
-{%- else %}
+{%-   if js_bindings_mode == "both" %}
+}
+{%-   endif %}
+
+{%- endif %}
+
+{%- if js_bindings_mode == "both" or js_bindings_mode == "old" %}
+{{"old"|set_current_mode}}
+
+{%-   if js_bindings_mode == "both" %}
+if (!mojo || !mojo.internal || !mojo.config) {
+{%-   endif %}
 
 define("{{module.path}}", [
 {%- if module.path !=
@@ -68,4 +84,8 @@ codec, core, validator
   return exports;
 });
 
+{%-   if js_bindings_mode == "both" %}
+}
+{%-   endif %}
+
 {%- endif %}