Implement cross-origin attributes using access check interceptors.

third_party/WebKit/Source/bindings/templates/methods.cpp.tmpl

Index: third_party/WebKit/Source/bindings/templates/methods.cpp.tmpl
diff --git a/third_party/WebKit/Source/bindings/templates/methods.cpp.tmpl b/third_party/WebKit/Source/bindings/templates/methods.cpp.tmpl
index c0457dc0a9a85a733a5342bb2bcbab1e309ee4fd..31b83ab1e466ab30ec32c0e3f60299cf421a8164 100644
--- a/third_party/WebKit/Source/bindings/templates/methods.cpp.tmpl
+++ b/third_party/WebKit/Source/bindings/templates/methods.cpp.tmpl
@@ -526,6 +526,9 @@ void {{method.name}}MethodCallback{{world_suffix}}(const v8::FunctionCallbackInf
 
 {##############################################################################}
 {% macro origin_safe_method_getter(method, world_suffix) %}
+{# TODO(dcheng): Currently, bindings must create a function object for each
+   realm as a hack to support the incumbent realm. Clean this up when Blink
+   properly supports the incumbent realm. #}
 static void {{method.name}}OriginSafeMethodGetter{{world_suffix}}(const v8::PropertyCallbackInfo<v8::Value>& info) {
   static int domTemplateKey; // This address is used for a key to look up the dom template.
   V8PerIsolateData* data = V8PerIsolateData::from(info.GetIsolate());