Make functions being routed by NativeHandlers throw an exception if there is no ModuleSystem in the…

chrome/renderer/module_system.h

 // 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.
 
 #ifndef CHROME_RENDERER_MODULE_SYSTEM_H_
 #define CHROME_RENDERER_MODULE_SYSTEM_H_
 #pragma once
 
 #include "base/compiler_specific.h"
 #include "base/memory/linked_ptr.h"
@@ skipping 36 matching lines @@
 
    private:
     ModuleSystem* module_system_;
     DISALLOW_COPY_AND_ASSIGN(NativesEnabledScope);
   };
 
   // |source_map| is a weak pointer.
   explicit ModuleSystem(v8::Handle<v8::Context> context, SourceMap* source_map);
   virtual ~ModuleSystem();
 
+  // Returns true if the current context has a ModuleSystem installed in it.
+  static bool IsPresentInCurrentContext();
+
   // Require the specified module. This is the equivalent of calling
   // require('module_name') from the loaded JS files.
   void Require(const std::string& module_name);
   v8::Handle<v8::Value> Require(const v8::Arguments& args);
   v8::Handle<v8::Value> RequireForJs(const v8::Arguments& args);
   v8::Handle<v8::Value> RequireForJsInner(v8::Handle<v8::String> module_name);
 
   // Register |native_handler| as a potential target for requireNative(), so
   // calls to requireNative(|name|) from JS will return a new object created by
   // |native_handler|.
@@ skipping 51 matching lines @@
   NativeHandlerMap native_handler_map_;
 
   // When 0, natives are disabled, otherwise indicates how many callers have
   // pinned natives as enabled.
   int natives_enabled_;
 
   DISALLOW_COPY_AND_ASSIGN(ModuleSystem);
 };
 
 #endif  // CHROME_RENDERER_MODULE_SYSTEM_H_