Prevent duplicate concurrent installs of the same extension

chrome/browser/apps/ephemeral_app_launcher.h

 // Copyright 2013 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_APPS_EPHEMERAL_APP_LAUNCHER_H_
 #define CHROME_BROWSER_APPS_EPHEMERAL_APP_LAUNCHER_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 98 matching lines @@
   void AbortLaunch(extensions::webstore_install::Result result,
                    const std::string& error);
 
   // Determines whether the app can be installed ephemerally.
   void CheckEphemeralInstallPermitted();
 
   // Install checker callback.
   void OnInstallChecked(int check_failures);
 
   // WebstoreStandaloneInstaller implementation.
+  virtual void InitInstallData(
+      extensions::ActiveInstallData* install_data) const OVERRIDE;
   virtual bool CheckRequestorAlive() const OVERRIDE;
   virtual const GURL& GetRequestorURL() const OVERRIDE;
   virtual bool ShouldShowPostInstallUI() const OVERRIDE;
   virtual bool ShouldShowAppInstalledBubble() const OVERRIDE;
   virtual content::WebContents* GetWebContents() const OVERRIDE;
   virtual scoped_refptr<ExtensionInstallPrompt::Prompt> CreateInstallPrompt()
       const OVERRIDE;
   virtual bool CheckInlineInstallPermitted(
       const base::DictionaryValue& webstore_data,
       std::string* error) const OVERRIDE;
@@ skipping 17 matching lines @@
   scoped_ptr<content::WebContents> dummy_web_contents_;
 
   scoped_ptr<ExtensionEnableFlow> extension_enable_flow_;
 
   scoped_ptr<extensions::ExtensionInstallChecker> install_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(EphemeralAppLauncher);
 };
 
 #endif  // CHROME_BROWSER_APPS_EPHEMERAL_APP_LAUNCHER_H_