Factor File API's 'partial interface URL' impl into separate files

third_party/WebKit/Source/bindings/templates/interface.h

 {% include 'copyright_block.txt' %}
 #ifndef {{v8_class}}_h
 #define {{v8_class}}_h
 
 {% for filename in header_includes %}
 #include "{{filename}}"
 {% endfor %}
 
 namespace blink {
 
@@ skipping 133 matching lines @@
     {# persistentHandleIndex must be the last field, if it is present.
        Detailed explanation: https://codereview.chromium.org/139173012
        FIXME: Remove this internal field, and share one field for either:
        * a persistent handle (if the object is in oilpan) or
        * a C++ pointer to the DOM object (if the object is not in oilpan) #}
     static const int internalFieldCount = v8DefaultWrapperInternalFieldCount + {{custom_internal_field_counter}};
     {# End custom internal fields #}
     static void installConditionallyEnabledProperties(v8::Local<v8::Object>, v8::Isolate*){% if has_conditional_attributes %};
     {% else %} { }
     {% endif %}
-    static void preparePrototypeAndInterfaceObject(v8::Local<v8::Context>, const DOMWrapperWorld&, v8::Local<v8::Object> prototypeObject, v8::Local<v8::Function> interfaceObject, v8::Local<v8::FunctionTemplate> interfaceTemplate){% if unscopeables or has_conditional_attributes_on_prototype or conditionally_enabled_methods %};
+    {{exported}}static void preparePrototypeAndInterfaceObject(v8::Local<v8::Context>, const DOMWrapperWorld&, v8::Local<v8::Object> prototypeObject, v8::Local<v8::Function> interfaceObject, v8::Local<v8::FunctionTemplate> interfaceTemplate){% if unscopeables or has_conditional_attributes_on_prototype or conditionally_enabled_methods %};
     {% else %} { }
     {% endif %}
     {% if has_partial_interface %}
     {{exported}}static void updateWrapperTypeInfo(InstallTemplateFunction, PreparePrototypeAndInterfaceObjectFunction);
     {{exported}}static void install{{v8_class}}Template(v8::Isolate*, const DOMWrapperWorld&, v8::Local<v8::FunctionTemplate> interfaceTemplate);
     {% for method in methods if method.overloads and method.overloads.has_partial_overloads %}
     {{exported}}static void register{{method.name | blink_capitalize}}MethodForPartialInterface(void (*)(const v8::FunctionCallbackInfo<v8::Value>&));
     {% endfor %}
     {% endif %}
     {% if has_partial_interface %}
 
 private:
     static InstallTemplateFunction install{{v8_class}}TemplateFunction;
     {% endif %}
 };
 
 {% if has_event_constructor %}
 {{exported}}bool initialize{{cpp_class}}({{cpp_class}}Init&, const Dictionary&, ExceptionState&, const v8::FunctionCallbackInfo<v8::Value>& info);
 
 {% endif %}
 template <>
 struct V8TypeOf<{{cpp_class}}> {
     typedef {{v8_class}} Type;
 };
 
 } // namespace blink
 
 #endif // {{v8_class}}_h