Move the event attach/detach logic on unload from event.js to

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"
 #include "extensions/renderer/script_context.h"
 #include "v8/include/v8.h"
 
 namespace extensions {
 
 namespace {
 // Key for the base::Bound routed function.
 const char* kHandlerFunction = "handler_function";
 }  // namespace
 
 ObjectBackedNativeHandler::ObjectBackedNativeHandler(ScriptContext* context)
     : router_data_(context->isolate()),
       context_(context),
       object_template_(context->isolate(),
                        v8::ObjectTemplate::New(context->isolate())) {
 }
 
-ObjectBackedNativeHandler::~ObjectBackedNativeHandler() { Invalidate(); }
+ObjectBackedNativeHandler::~ObjectBackedNativeHandler() {
+}
 
 v8::Handle<v8::Object> ObjectBackedNativeHandler::NewInstance() {
   return v8::Local<v8::ObjectTemplate>::New(GetIsolate(), object_template_)
       ->NewInstance();
 }
 
 // static
 void ObjectBackedNativeHandler::Router(
     const v8::FunctionCallbackInfo<v8::Value>& args) {
   v8::HandleScope handle_scope(args.GetIsolate());
@@ skipping 29 matching lines @@
   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() {
-  if (!is_valid())
-    return;
-  v8::Isolate* isolate = v8::Isolate::GetCurrent();
+  CHECK(is_valid());
+
+  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::Handle<v8::Object> data = router_data_.Get(i);
     v8::Handle<v8::Value> handler_function_value =
         data->Get(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));
   }
+
   router_data_.Clear();
   object_template_.Reset();
-  context_ = NULL;
+
   NativeHandler::Invalidate();
 }
 
 }  // namespace extensions