bindings: Remove [EventConstructor] and [InitializedByEventConstructor]

Source/bindings/templates/interface_base.cpp

 {% include 'copyright_block.txt' %}
 #include "config.h"
 {% filter conditional(conditional_string) %}
 #include "{{v8_class_or_partial}}.h"
 
 {% for filename in cpp_includes if filename != '%s.h' % cpp_class_or_partial %}
 #include "{{filename}}"
 {% endfor %}
 
 namespace blink {
@@ skipping 245 matching lines @@
     {{method_configuration(method)}},
     {% endfilter %}
     {% endfor %}
 };
 
 {% endif %}
 {% endblock %}
 {% endif %}{# not is_array_buffer_or_view #}
 {##############################################################################}
 {% block named_constructor %}{% endblock %}
-{% block initialize_event %}{% endblock %}
 {% block constructor_callback %}{% endblock %}
 {% block configure_shadow_object_template %}{% endblock %}
 {##############################################################################}
 {% block install_dom_template %}
 {% if not is_array_buffer_or_view %}
 {% from 'methods.cpp' import install_custom_signature with context %}
 {% from 'attributes.cpp' import attribute_configuration with context %}
 {% from 'constants.cpp' import install_constants with context %}
 {% if has_partial_interface or is_partial %}
 void {{v8_class_or_partial}}::install{{v8_class}}Template(v8::Local<v8::FunctionTemplate> functionTemplate, v8::Isolate* isolate)
@@ skipping 217 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 %}