Prune shared extendion module after extension updating.

chrome/browser/extensions/external_install_manager.cc

 // 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.
 
 #include "chrome/browser/extensions/external_install_manager.h"
 
 #include <string>
 
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
@@ skipping 157 matching lines @@
   AcknowledgeExternalExtension(extension->id());
   LogExternalExtensionEvent(extension, EXTERNAL_EXTENSION_REENABLED);
 
   // If we had an error for this extension, remove it.
   if (error_.get() && extension->id() == error_->extension_id())
     RemoveExternalInstallError();
 }
 
 void ExternalInstallManager::OnExtensionInstalled(
     content::BrowserContext* browser_context,
-    const Extension* extension) {
+    const Extension* extension,
+    bool is_update) {
   // Certain extension locations are specific enough that we can
   // auto-acknowledge any extension that came from one of them.
   if (Manifest::IsPolicyLocation(extension->location()) ||
       extension->location() == Manifest::EXTERNAL_COMPONENT) {
     AcknowledgeExternalExtension(extension->id());
     return;
   }
 
   if (!IsUnacknowledgedExternalExtension(extension))
     return;
@@ skipping 31 matching lines @@
   // registry observer) for this, but the ExtensionUnloaded notification is
   // not sent out if the extension is disabled (which it is here).
   if (error_.get() &&
       content::Details<const Extension>(details).ptr()->id() ==
           error_->extension_id()) {
     RemoveExternalInstallError();
   }
 }
 
 }  // namespace extensions