Fixing crash on sync when app becomes extension or vice versa.

chrome/browser/extensions/extension_service.cc

 // Copyright (c) 2011 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 <set>
 
 #include "base/basictypes.h"
@@ skipping 1873 matching lines @@
     extension_sync_list.push_back(i->second);
   }
 
   return extension_sync_list;
 }
 
 void ExtensionService::ProcessExtensionSyncData(
     const ExtensionSyncData& extension_sync_data,
     SyncBundle& bundle) {
   const std::string& id = extension_sync_data.id();
+  const Extension* extension = GetInstalledExtension(id);
+
+  // TODO(bolms): we should really handle this better.  The particularly bad
+  // case is where an app becomes an extension or vice versa, and we end up with
+  // a zombie extension that won't go away.
+  if (extension && !bundle.filter(*extension))
+    return;
 
   // Handle uninstalls first.
   if (extension_sync_data.uninstalled()) {
     std::string error;
     if (!UninstallExtensionHelper(this, id)) {
       LOG(WARNING) << "Could not uninstall extension " << id
                    << " for sync";
     }
     return;
   }
 
   // Set user settings.
   if (extension_sync_data.enabled()) {
     EnableExtension(id);
   } else {
     DisableExtension(id);
   }
   SetIsIncognitoEnabled(id, extension_sync_data.incognito_enabled());
 
-  const Extension* extension = GetInstalledExtension(id);
   if (extension) {
     // If the extension is already installed, check if it's outdated.
     int result = extension->version()->CompareTo(extension_sync_data.version());
     if (result < 0) {
       // Extension is outdated.
       bundle.pending_sync_data[extension_sync_data.id()] = extension_sync_data;
       CheckForUpdatesSoon();
     }
   } else {
     // TODO(akalin): Replace silent update with a list of enabled
@@ skipping 927 matching lines @@
 
 ExtensionService::NaClModuleInfoList::iterator
     ExtensionService::FindNaClModule(const GURL& url) {
   for (NaClModuleInfoList::iterator iter = nacl_module_list_.begin();
        iter != nacl_module_list_.end(); ++iter) {
     if (iter->url == url)
       return iter;
   }
   return nacl_module_list_.end();
 }