Switch RemoteWindowProxy to use v8::Context::NewRemoteContext.

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 a036d5839d10565c153094f907d8123dcc7e408e..b0e138457b2f328acd4606e122418b3ff82be430 100644
--- a/third_party/WebKit/Source/bindings/templates/methods.cpp.tmpl
+++ b/third_party/WebKit/Source/bindings/templates/methods.cpp.tmpl
@@ -21,7 +21,7 @@ static void {{method.name}}{{method.overload_index}}Method{{world_suffix}}(const
   {% endif %}
 
   {% if not method.is_static %}
-  {% if method.returns_promise %}
+  {% if method.returns_promise or (interface_name == 'Window' and method.is_cross_origin) %}
   // V8DOMConfiguration::DoNotCheckHolder
   // Make sure that info.Holder() really points to an instance of the type.
   if (!{{v8_class}}::hasInstance(info.Holder(), info.GetIsolate())) {
@@ -547,8 +547,16 @@ static void {{method.name}}OriginSafeMethodGetter{{world_suffix}}(const v8::Prop
   static int domTemplateKey; // This address is used for a key to look up the dom template.
   V8PerIsolateData* data = V8PerIsolateData::from(info.GetIsolate());
   const DOMWrapperWorld& world = DOMWrapperWorld::world(info.GetIsolate()->GetCurrentContext());
+{% if interface_name == 'Window' %}
+  // Note: signature is intentionally omitted when creating origin-safe methods.
+  // A remote context's global proxy does not have the standard prototype chain
+  // set up, so v8 won't be able to find the receiver type in the prototype
+  // chain. Instead, the method implementation must do the check manually.
+  v8::Local<v8::Signature> signature;
+{% else %}
   v8::Local<v8::FunctionTemplate> interfaceTemplate = data->findInterfaceTemplate(world, &{{v8_class}}::wrapperTypeInfo);
   v8::Local<v8::Signature> signature = v8::Signature::New(info.GetIsolate(), interfaceTemplate);
+{% endif %}
 
   v8::Local<v8::FunctionTemplate> methodTemplate = data->findOrCreateOperationTemplate(world, &domTemplateKey, {{v8_class_or_partial}}::{{method.name}}MethodCallback{{world_suffix}}, v8Undefined(), signature, {{method.length}});
   // Return the function by default, unless the user script has overwritten it.