Use WebFrame::setIsolatedWorldSecurityOrigin to allow cross-origin XHRs in content scripts.

chrome/renderer/extensions/user_script_slave.h

 // Copyright (c) 2011 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_EXTENSIONS_USER_SCRIPT_SLAVE_H_
 #define CHROME_RENDERER_EXTENSIONS_USER_SCRIPT_SLAVE_H_
 #pragma once
 
 #include <set>
 #include <string>
 #include <vector>
 
 #include "base/memory/scoped_ptr.h"
 #include "base/shared_memory.h"
 #include "base/stl_util-inl.h"
 #include "base/string_piece.h"
 #include "chrome/common/extensions/user_script.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebScriptSource.h"
 
+class Extension;
 class ExtensionSet;
 
 namespace WebKit {
 class WebFrame;
 }
 
 using WebKit::WebScriptSource;
 
 // Manages installed UserScripts for a render process.
 class UserScriptSlave {
  public:
-  UserScriptSlave(const ExtensionSet* extensions);
+  explicit UserScriptSlave(const ExtensionSet* extensions);
   ~UserScriptSlave();
 
   // Returns the unique set of extension IDs this UserScriptSlave knows about.
   void GetActiveExtensions(std::set<std::string>* extension_ids);
 
   // Update the parsed scripts from shared memory.
   bool UpdateScripts(base::SharedMemoryHandle shared_memory);
 
   // Inject the appropriate scripts into a frame based on its URL.
   // TODO(aa): Extract a UserScriptFrame interface out of this to improve
   // testability.
   void InjectScripts(WebKit::WebFrame* frame, UserScript::RunLocation location);
 
-  static int GetIsolatedWorldId(const std::string& extension_id);
+  // Gets the isolated world ID to use for the given |extension| in the given
+  // |frame|. If no isolated world has been created for that extension,
+  // one will be created and initialized.
+  static int GetIsolatedWorldId(const Extension* extension,
+                                WebKit::WebFrame* frame);
 
   static void InsertInitExtensionCode(std::vector<WebScriptSource>* sources,
                                       const std::string& extension_id);
  private:
+  static void InitializeIsolatedWorld(int isolated_world_id,
+                                      const Extension* extension);
+
   // Shared memory containing raw script data.
   scoped_ptr<base::SharedMemory> shared_memory_;
 
   // Parsed script data.
   std::vector<UserScript*> scripts_;
   STLElementDeleter<std::vector<UserScript*> > script_deleter_;
 
   // Greasemonkey API source that is injected with the scripts.
   base::StringPiece api_js_;
 
   // Extension metadata.
   const ExtensionSet* extensions_;
 
   DISALLOW_COPY_AND_ASSIGN(UserScriptSlave);
 };
 
 #endif  // CHROME_RENDERER_EXTENSIONS_USER_SCRIPT_SLAVE_H_