[gin] Allow interceptors to signal whether a they intercepted something

gin/object_template_builder.cc

 // Copyright 2013 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.
 
 #include "gin/object_template_builder.h"
 
 #include "gin/interceptor.h"
 #include "gin/per_isolate_data.h"
 #include "gin/public/wrapper_info.h"
 
@@ skipping 51 matching lines @@
 void NamedPropertySetter(v8::Local<v8::String> property,
                          v8::Local<v8::Value> value,
                          const v8::PropertyCallbackInfo<v8::Value>& info) {
   v8::Isolate* isolate = info.GetIsolate();
   NamedPropertyInterceptor* interceptor =
       NamedInterceptorFromV8(isolate, info.Holder());
   if (!interceptor)
     return;
   std::string name;
   ConvertFromV8(isolate, property, &name);
-  interceptor->SetNamedProperty(isolate, name, value);
+  if (interceptor->SetNamedProperty(isolate, name, value))
+    info.GetReturnValue().Set(value);
 }
 
 void NamedPropertyQuery(v8::Local<v8::String> property,
                         const v8::PropertyCallbackInfo<v8::Integer>& info) {
   v8::Isolate* isolate = info.GetIsolate();
   NamedPropertyInterceptor* interceptor =
       NamedInterceptorFromV8(isolate, info.Holder());
   if (!interceptor)
     return;
   std::string name;
@@ skipping 24 matching lines @@
 }
 
 void IndexedPropertySetter(uint32_t index,
                            v8::Local<v8::Value> value,
                            const v8::PropertyCallbackInfo<v8::Value>& info) {
   v8::Isolate* isolate = info.GetIsolate();
   IndexedPropertyInterceptor* interceptor =
       IndexedInterceptorFromV8(isolate, info.Holder());
   if (!interceptor)
     return;
-  interceptor->SetIndexedProperty(isolate, index, value);
+  if (interceptor->SetIndexedProperty(isolate, index, value))
+    info.GetReturnValue().Set(value);
 }
 
 void IndexedPropertyEnumerator(
     const v8::PropertyCallbackInfo<v8::Array>& info) {
   v8::Isolate* isolate = info.GetIsolate();
   IndexedPropertyInterceptor* interceptor =
       IndexedInterceptorFromV8(isolate, info.Holder());
   if (!interceptor)
     return;
   info.GetReturnValue().Set(v8::Handle<v8::Array>::Cast(
@@ skipping 42 matching lines @@
   return *this;
 }
 
 v8::Local<v8::ObjectTemplate> ObjectTemplateBuilder::Build() {
   v8::Local<v8::ObjectTemplate> result = template_;
   template_.Clear();
   return result;
 }
 
 }  // namespace gin