Enable <webview>.executeScript outside of Apps and Extensions [1]

extensions/renderer/web_ui_injection_host.h

 // Copyright 2015 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 EXTENSIONS_RENDERER_WEBUI_INJECTION_HOST_H_
 #define EXTENSIONS_RENDERER_WEBUI_INJECTION_HOST_H_
 
 #include "extensions/renderer/injection_host.h"
 
 class WebUIInjectionHost : public InjectionHost {
  public:
   WebUIInjectionHost(const HostID& host_id);
   ~WebUIInjectionHost() override;
 
+  static scoped_ptr<const InjectionHost> Create(const HostID& host_id);
+
  private:
   // InjectionHost:
   std::string GetContentSecurityPolicy() const override;
   const GURL& url() const override;
   const std::string& name() const override;
   extensions::PermissionsData::AccessType CanExecuteOnFrame(
       const GURL& document_url,
       const GURL& top_frame_url,
       int tab_id,
       bool is_declarative) const override;
   bool ShouldNotifyBrowserOfInjection() const override;
 
  private:
   GURL url_;
 
   DISALLOW_COPY_AND_ASSIGN(WebUIInjectionHost);
 };
 
 #endif  // EXTENSIONS_RENDERER_WEBUI_INJECTION_HOST_H_