Allow the user to "repair" a corrupted extension.

chrome/browser/extensions/extension_service.cc

 // Copyright (c) 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.
 
 #include "chrome/browser/extensions/extension_service.h"
 
 #include <algorithm>
 #include <iterator>
 #include <set>
 
@@ skipping 700 matching lines @@
   // |external_uninstall| to true so this is the only way to uninstall
   // managed extensions.
   // Shared modules being uninstalled will also set |external_uninstall| to true
   // so that we can guarantee users don't uninstall a shared module.
   // (crbug.com/273300)
   // TODO(rdevlin.cronin): This is probably not right. We should do something
   // else, like include an enum IS_INTERNAL_UNINSTALL or IS_USER_UNINSTALL so
   // we don't do this.
   bool external_uninstall =
       (reason == extensions::UNINSTALL_REASON_INTERNAL_MANAGEMENT) ||
+      (reason == extensions::UNINSTALL_REASON_REINSTALL) ||
       (reason == extensions::UNINSTALL_REASON_ORPHANED_EXTERNAL_EXTENSION) ||
       (reason == extensions::UNINSTALL_REASON_ORPHANED_SHARED_MODULE) ||
       (reason == extensions::UNINSTALL_REASON_SYNC &&
            extension->was_installed_by_custodian());
   if (!external_uninstall &&
       !system_->management_policy()->UserMayModifySettings(
         extension.get(), error)) {
     content::NotificationService::current()->Notify(
         extensions::NOTIFICATION_EXTENSION_UNINSTALL_NOT_ALLOWED,
         content::Source<Profile>(profile_),
         content::Details<const Extension>(extension.get()));
     return false;
   }
 
   syncer::SyncChange sync_change;
-  if (extension_sync_service_) {
+  // Don't sync the uninstall if we're going to reinstall the extension
+  // momentarily.
+  if (extension_sync_service_ &&
+      reason != extensions::UNINSTALL_REASON_REINSTALL) {
      sync_change = extension_sync_service_->PrepareToSyncUninstallExtension(
         extension.get(), is_ready());
   }
 
   system_->install_verifier()->Remove(extension->id());
 
   UMA_HISTOGRAM_ENUMERATION("Extensions.UninstallType",
                             extension->GetType(), 100);
   RecordPermissionMessagesHistogram(extension.get(),
                                     "Extensions.Permissions_Uninstall2");
@@ skipping 20 matching lines @@
   UntrackTerminatedExtension(extension->id());
 
   // Notify interested parties that we've uninstalled this extension.
   content::NotificationService::current()->Notify(
       extensions::NOTIFICATION_EXTENSION_UNINSTALLED_DEPRECATED,
       content::Source<Profile>(profile_),
       content::Details<const Extension>(extension.get()));
   ExtensionRegistry::Get(profile_)
       ->TriggerOnUninstalled(extension.get(), reason);
 
-  if (extension_sync_service_) {
+  if (sync_change.IsValid()) {
     extension_sync_service_->ProcessSyncUninstallExtension(extension->id(),
                                                            sync_change);
   }
 
   delayed_installs_.Remove(extension->id());
 
   extension_prefs_->OnExtensionUninstalled(
       extension->id(), extension->location(), external_uninstall);
 
   // Track the uninstallation.
@@ skipping 1566 matching lines @@
 }
 
 void ExtensionService::OnProfileDestructionStarted() {
   ExtensionIdSet ids_to_unload = registry_->enabled_extensions().GetIDs();
   for (ExtensionIdSet::iterator it = ids_to_unload.begin();
        it != ids_to_unload.end();
        ++it) {
     UnloadExtension(*it, UnloadedExtensionInfo::REASON_PROFILE_SHUTDOWN);
   }
 }