[Extensions] Make handler_function a hidden property

extensions/renderer/object_backed_native_handler.cc

 // Copyright 2014 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 "extensions/renderer/object_backed_native_handler.h"
 
 #include "base/logging.h"
 #include "base/memory/linked_ptr.h"
 #include "extensions/renderer/console.h"
 #include "extensions/renderer/module_system.h"
@@ skipping 23 matching lines @@
       ->NewInstance();
 }
 
 // static
 void ObjectBackedNativeHandler::Router(
     const v8::FunctionCallbackInfo<v8::Value>& args) {
   v8::HandleScope handle_scope(args.GetIsolate());
   v8::Local<v8::Object> data = args.Data().As<v8::Object>();
 
   v8::Local<v8::Value> handler_function_value =
-      data->Get(v8::String::NewFromUtf8(args.GetIsolate(), kHandlerFunction));
+      data->GetHiddenValue(
+          v8::String::NewFromUtf8(args.GetIsolate(), kHandlerFunction));
   // See comment in header file for why we do this.
   if (handler_function_value.IsEmpty() ||
       handler_function_value->IsUndefined()) {
     ScriptContext* script_context = ScriptContextSet::GetContextByV8Context(
         args.GetIsolate()->GetCurrentContext());
     console::Error(script_context ? script_context->GetRenderFrame() : nullptr,
                    "Extension view no longer exists");
     return;
   }
-  DCHECK(handler_function_value->IsExternal());
+  // This CHECK is *important*. Otherwise, we'll go around happily executing
+  // something random.  See crbug.com/548273.
+  CHECK(handler_function_value->IsExternal());
   static_cast<HandlerFunction*>(
       handler_function_value.As<v8::External>()->Value())->Run(args);
 }
 
 void ObjectBackedNativeHandler::RouteFunction(
     const std::string& name,
     const HandlerFunction& handler_function) {
   v8::Isolate* isolate = v8::Isolate::GetCurrent();
   v8::HandleScope handle_scope(isolate);
   v8::Context::Scope context_scope(context_->v8_context());
 
   v8::Local<v8::Object> data = v8::Object::New(isolate);
-  data->Set(
+  data->SetHiddenValue(
       v8::String::NewFromUtf8(isolate, kHandlerFunction),
       v8::External::New(isolate, new HandlerFunction(handler_function)));
   v8::Local<v8::FunctionTemplate> function_template =
       v8::FunctionTemplate::New(isolate, Router, data);
   v8::Local<v8::ObjectTemplate>::New(isolate, object_template_)
       ->Set(isolate, name.c_str(), function_template);
   router_data_.Append(data);
 }
 
 v8::Isolate* ObjectBackedNativeHandler::GetIsolate() const {
   return context_->isolate();
 }
 
 void ObjectBackedNativeHandler::Invalidate() {
   v8::Isolate* isolate = GetIsolate();
   v8::HandleScope handle_scope(isolate);
   v8::Context::Scope context_scope(context_->v8_context());
 
   for (size_t i = 0; i < router_data_.Size(); i++) {
     v8::Local<v8::Object> data = router_data_.Get(i);
     v8::Local<v8::Value> handler_function_value =
-        data->Get(v8::String::NewFromUtf8(isolate, kHandlerFunction));
+        data->GetHiddenValue(
+            v8::String::NewFromUtf8(isolate, kHandlerFunction));
     CHECK(!handler_function_value.IsEmpty());
     delete static_cast<HandlerFunction*>(
         handler_function_value.As<v8::External>()->Value());
-    data->Delete(v8::String::NewFromUtf8(isolate, kHandlerFunction));
+    data->DeleteHiddenValue(v8::String::NewFromUtf8(isolate, kHandlerFunction));
   }
 
   router_data_.Clear();
   object_template_.Reset();
 
   NativeHandler::Invalidate();
 }
 
 }  // namespace extensions