Add IsEmpty() check to ModuleSystem::IsPresentInCurrentContext().

chrome/renderer/extensions/module_system.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/module_system.h"
 
 #include "base/bind.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebScopedMicrotaskSuppression.h"
 
 namespace {
@@ skipping 38 matching lines @@
 }
 
 ModuleSystem::NativesEnabledScope::~NativesEnabledScope() {
   module_system_->natives_enabled_--;
   CHECK_GE(module_system_->natives_enabled_, 0);
 }
 
 // static
 bool ModuleSystem::IsPresentInCurrentContext() {
   v8::Handle<v8::Object> global(v8::Context::GetCurrent()->Global());
+  if (global.IsEmpty())
+    return false;
   v8::Handle<v8::Value> module_system =
       global->GetHiddenValue(v8::String::New(kModuleSystem));
   return !module_system.IsEmpty() && !module_system->IsUndefined();
 }
 
 // static
 void ModuleSystem::DumpException(const v8::TryCatch& try_catch) {
   v8::HandleScope handle_scope;
 
   v8::Handle<v8::Message> message(try_catch.Message());
@@ skipping 220 matching lines @@
   v8::Handle<v8::String> right = v8::String::New("\n})");
   return handle_scope.Close(
       v8::String::Concat(left, v8::String::Concat(source, right)));
 }
 
 v8::Handle<v8::Value> ModuleSystem::ThrowException(const std::string& message) {
   return v8::ThrowException(v8::String::New(message.c_str()));
 }
 
 }  // extensions