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

extensions/renderer/extension_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_EXTENSION_INJECTION_HOST_H_
 #define EXTENSIONS_RENDERER_EXTENSION_INJECTION_HOST_H_
 
 #include "base/memory/ref_counted.h"
 #include "extensions/common/extension.h"
 #include "extensions/renderer/injection_host.h"
 
 namespace extensions {
 class ExtensionSet;
 
+class ExtensionSet;
+
 // A wrapper class that holds an extension and implements the InjectionHost
 // interface.
 class ExtensionInjectionHost : public InjectionHost {
  public:
   ExtensionInjectionHost(const Extension* extension);
   ~ExtensionInjectionHost() override;
 
   // Create an ExtensionInjectionHost object. If the extension is gone, returns
   // a null scoped ptr.
-  static scoped_ptr<const ExtensionInjectionHost> Create(
-      const std::string& extension_id, const ExtensionSet* extensions);
+  static scoped_ptr<const InjectionHost> Create(const std::string& extension_id,
+                                                const ExtensionSet* extensions);
 
  private:
   // InjectionHost:
   std::string GetContentSecurityPolicy() const override;
   const GURL& url() const override;
   const std::string& name() const override;
   PermissionsData::AccessType CanExecuteOnFrame(
       const GURL& document_url,
       const GURL& top_frame_url,
       int tab_id,
       bool is_declarative) const override;
   bool ShouldNotifyBrowserOfInjection() const override;
 
   const Extension* extension_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionInjectionHost);
 };
 
 }  // namespace extesions
 
 #endif  // EXTENSIONS_RENDERER_EXTENSION_INJECTION_HOST_H_