Allow extension overinstall

chrome/browser/extensions/extension_install_ui.h

 // Copyright (c) 2010 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_EXTENSION_INSTALL_UI_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_INSTALL_UI_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 55 matching lines @@
   // We *MUST* eventually call either Proceed() or Abort()
   // on |delegate|.
   virtual void ConfirmUninstall(Delegate* delegate, Extension* extension);
 
   // Installation was successful. This is declared virtual for testing.
   virtual void OnInstallSuccess(Extension* extension);
 
   // Installation failed. This is declared virtual for testing.
   virtual void OnInstallFailure(const std::string& error);
 
-  // The install was rejected because the same extension/version is already
-  // installed. This is declared virtual for testing.
-  virtual void OnOverinstallAttempted(Extension* extension);
-
   // ImageLoadingTracker::Observer overrides.
   virtual void OnImageLoaded(
       SkBitmap* image, ExtensionResource resource, int index);
 
   // Show an infobar for a newly-installed theme.  previous_theme_id
   // should be empty if the previous theme was the system/default
   // theme.
   //
   // TODO(akalin): Find a better home for this (and
   // GetNewThemeInstalledInfoBarDelegate()).
@@ skipping 43 matching lines @@
   Delegate* delegate_;    // The delegate we will call Proceed/Abort on after
                           // confirmation UI.
   PromptType prompt_type_;  // The type of prompt we are going to show.
 
   // Keeps track of extension images being loaded on the File thread for the
   // purpose of showing the install UI.
   ImageLoadingTracker tracker_;
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_INSTALL_UI_H_