Prevent ObjectBackedNativeHandler from calling itself once invalid.

chrome/renderer/extensions/v8_schema_registry.cc

 // Copyright (c) 2012 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 "chrome/renderer/extensions/v8_schema_registry.h"
 
 #include "base/logging.h"
 #include "base/values.h"
 #include "chrome/common/extensions/api/extension_api.h"
 #include "content/public/renderer/v8_value_converter.h"
 
 using content::V8ValueConverter;
 
 namespace extensions {
 
 V8SchemaRegistry::V8SchemaRegistry() {}
 
 V8SchemaRegistry::~V8SchemaRegistry() {
   v8::HandleScope handle_scope;
+
   for (SchemaCache::iterator i = schema_cache_.begin();
        i != schema_cache_.end(); ++i) {
     i->second.Dispose(i->second->CreationContext()->GetIsolate());
   }
 }
 
 v8::Handle<v8::Array> V8SchemaRegistry::GetSchemas(
     const std::set<std::string>& apis) {
   v8::HandleScope handle_scope;
   v8::Context::Scope context_scope(GetOrCreateContext());
+
   v8::Handle<v8::Array> v8_apis(v8::Array::New(apis.size()));
   size_t api_index = 0;
   for (std::set<std::string>::const_iterator i = apis.begin(); i != apis.end();
       ++i) {
     v8_apis->Set(api_index++, GetSchema(*i));
   }
-  return v8_apis;
+  return handle_scope.Close(v8_apis);
 }
 
 v8::Handle<v8::Object> V8SchemaRegistry::GetSchema(const std::string& api) {
   v8::HandleScope handle_scope;
+
   SchemaCache::iterator maybe_schema = schema_cache_.find(api);
   if (maybe_schema != schema_cache_.end())
-    return maybe_schema->second;
+    return handle_scope.Close(maybe_schema->second);
+
+  v8::Persistent<v8::Context> context = GetOrCreateContext();
+  v8::Context::Scope context_scope(context);
 
   const base::DictionaryValue* schema =
       ExtensionAPI::GetSharedInstance()->GetSchema(api);
   CHECK(schema) << api;
-
-  v8::Persistent<v8::Context> context = GetOrCreateContext();
-  v8::Context::Scope context_scope(context);
-
   scoped_ptr<V8ValueConverter> v8_value_converter(V8ValueConverter::create());
   v8::Handle<v8::Value> value = v8_value_converter->ToV8Value(schema, context);
   CHECK(!value.IsEmpty());
 
   v8::Persistent<v8::Object> v8_schema = v8::Persistent<v8::Object>::New(
       context->GetIsolate(), v8::Handle<v8::Object>::Cast(value));
   schema_cache_[api] = v8_schema;
-  return v8_schema;
+  return handle_scope.Close(v8_schema);
 }
 
 v8::Persistent<v8::Context> V8SchemaRegistry::GetOrCreateContext() {
   if (context_.get().IsEmpty())
     context_.reset(v8::Context::New());
   return context_.get();
 }
 
 }  // namespace extensions