Extract executeScript-like functionality into a single ExtensionScriptExecutor class.

chrome/browser/extensions/execute_code_in_tab_function.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_BROWSER_EXTENSIONS_EXECUTE_CODE_IN_TAB_FUNCTION_H__
 #define CHROME_BROWSER_EXTENSIONS_EXECUTE_CODE_IN_TAB_FUNCTION_H__
 #pragma once
 
 #include <string>
 
 #include "chrome/browser/extensions/extension_function.h"
 #include "chrome/common/extensions/extension_resource.h"
 #include "chrome/common/extensions/user_script.h"
-#include "content/public/browser/web_contents_observer.h"
 
 // Implement API call tabs.executeScript and tabs.insertCSS.
-class ExecuteCodeInTabFunction : public AsyncExtensionFunction,
-                                 public content::WebContentsObserver {
+class ExecuteCodeInTabFunction : public AsyncExtensionFunction {
  public:
   ExecuteCodeInTabFunction();
 
  protected:
   virtual ~ExecuteCodeInTabFunction();
 
   // ExtensionFunction:
   virtual bool RunImpl() OVERRIDE;
 
  private:
-  // content::WebContentsObserver overrides.
-  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
-
   // Message handler.
-  void OnExecuteCodeFinished(int request_id, bool success,
-                             const std::string& error);
+  void OnExecuteCodeFinished(bool success, const std::string& error);
 
   // Called when contents from the file whose path is specified in JSON
   // arguments has been loaded.
   void DidLoadFile(bool success, const std::string& data);
 
   // Runs on FILE thread. Loads message bundles for the extension and
   // localizes the CSS data. Calls back DidLoadAndLocalizeFile on the UI thread.
   void LocalizeCSS(
       const std::string& data,
       const std::string& extension_id,
@@ skipping 30 matching lines @@
 };
 
 class TabsInsertCSSFunction : public ExecuteCodeInTabFunction {
  private:
   virtual ~TabsInsertCSSFunction() {}
 
   DECLARE_EXTENSION_FUNCTION_NAME("tabs.insertCSS")
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXECUTE_CODE_IN_TAB_FUNCTION_H__