Prune shared extendion module after extension updating.

chrome/browser/extensions/external_install_manager.h

 // Copyright 2014 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_EXTERNAL_INSTALL_MANAGER_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTERNAL_INSTALL_MANAGER_H_
 
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/scoped_observer.h"
@@ skipping 41 matching lines @@
   const ExternalInstallError* error() { return error_.get(); }
 
   // Returns a mutable copy of the error for testing purposes.
   ExternalInstallError* error_for_testing() { return error_.get(); }
 
  private:
   // ExtensionRegistryObserver implementation.
   virtual void OnExtensionLoaded(content::BrowserContext* browser_context,
                                  const Extension* extension) OVERRIDE;
   virtual void OnExtensionInstalled(content::BrowserContext* browser_context,
-                                    const Extension* extension) OVERRIDE;
+                                    const Extension* extension,
+                                    bool is_update) OVERRIDE;
   virtual void OnExtensionUninstalled(content::BrowserContext* browser_context,
                                       const Extension* extension) OVERRIDE;
 
   // content::NotificationObserver implementation.
   virtual void Observe(int type,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
   // Adds a global error informing the user that an external extension was
   // installed. If |is_new_profile| is true, then this error is from the first
@@ skipping 20 matching lines @@
 
   ScopedObserver<ExtensionRegistry, ExtensionRegistryObserver>
       extension_registry_observer_;
 
   DISALLOW_COPY_AND_ASSIGN(ExternalInstallManager);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTERNAL_INSTALL_MANAGER_H_