[DO NOT LAND] Set @@toStringTag for DOM object prototypes

Source/bindings/templates/interface_base.cpp

 // 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.
 
 // This file has been auto-generated by {{code_generator}}. DO NOT MODIFY!
 
 #include "config.h"
 {% filter conditional(conditional_string) %}
 #include "{{v8_class_or_partial}}.h"
 
@@ skipping 450 matching lines @@
 
     prototypeTemplate->SetInternalFieldCount(V8Window::internalFieldCount);
     functionTemplate->SetHiddenPrototype(true);
     instanceTemplate->SetInternalFieldCount(V8Window::internalFieldCount);
     {% elif interface_name in [
            'HTMLDocument', 'DedicatedWorkerGlobalScope',
            'SharedWorkerGlobalScope', 'ServiceWorkerGlobalScope'] %}
     functionTemplate->SetHiddenPrototype(true);
     {% endif %}
 
+    {# WebIDL 4.7:
+                The class string of a platform object that implements
+                one or more interfaces must be the identifier of the
+                primary interface of the platform object. #}
+    instanceTemplate->Set(v8::Symbol::GetToStringTag(isolate), v8AtomicString(isolate, "{{interface_name}}"));

[haraken, 2015/03/19 23:30:56]

Just to confirm: What is the interface_name of WebKitTransitionEvent?
WebKitTransitionEvent is an alias of TransitionEvent, and I'm curious how the
alias is handled.

https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit...

+
+    {# WebIDL 4.5.4:
+                The class string of an interface prototype object is the
+                concatenation of the interface’s identifier and the string
+                "Prototype". #}
+    prototypeTemplate->Set(v8::Symbol::GetToStringTag(isolate), v8AtomicString(isolate, "{{interface_name}}Prototype"));
+
     // Custom toString template
     functionTemplate->Set(v8AtomicString(isolate, "toString"), V8PerIsolateData::from(isolate)->toStringTemplate());
     {% endif %}
 }
 
 {% endif %}{# not is_array_buffer_or_view #}
 {% endblock %}
 {##############################################################################}
 {% block get_dom_template %}{% endblock %}
 {% block has_instance %}{% endblock %}
@@ skipping 18 matching lines @@
 {% endfor %}
 {% for attribute in attributes if attribute.is_implemented_in_private_script %}
 {{attribute_getter_implemented_in_private_script(attribute)}}
 {% if attribute.has_setter %}
 {{attribute_setter_implemented_in_private_script(attribute)}}
 {% endif %}
 {% endfor %}
 {% block partial_interface %}{% endblock %}
 } // namespace blink
 {% endfilter %}