Don't crash when trying to create an ExtensionSyncData from invalid SyncData.

chrome/browser/extensions/extension_sync_bundle.cc

 // Copyright (c) 2012 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_sync_bundle.h"
 
 #include "base/location.h"
 #include "chrome/browser/extensions/extension_sync_service.h"
 #include "chrome/browser/extensions/extension_util.h"
 #include "chrome/browser/profiles/profile.h"
@@ skipping 14 matching lines @@
 void ExtensionSyncBundle::SetupSync(
     syncer::SyncChangeProcessor* sync_processor,
     syncer::SyncErrorFactory* sync_error_factory,
     const syncer::SyncDataList& initial_sync_data) {
   sync_processor_.reset(sync_processor);
   sync_error_factory_.reset(sync_error_factory);
 
   for (syncer::SyncDataList::const_iterator i = initial_sync_data.begin();
        i != initial_sync_data.end();
        ++i) {
-    ExtensionSyncData extension_sync_data(*i);
-    AddExtension(extension_sync_data.id());
-    extension_sync_service_->ProcessExtensionSyncData(extension_sync_data);
+    scoped_ptr<ExtensionSyncData> extension_sync_data(
+        ExtensionSyncData::CreateFromSyncData(*i));
+    if (extension_sync_data.get()) {
+      AddExtension(extension_sync_data->id());
+      extension_sync_service_->ProcessExtensionSyncData(*extension_sync_data);
+    }
   }
 }
 
 void ExtensionSyncBundle::Reset() {
   sync_processor_.reset();
   sync_error_factory_.reset();
   synced_extensions_.clear();
   pending_sync_data_.clear();
 }
 
@@ skipping 119 matching lines @@
 void ExtensionSyncBundle::RemoveExtension(const std::string& id) {
   synced_extensions_.erase(id);
 }
 
 void ExtensionSyncBundle::MarkPendingExtensionSynced(const std::string& id) {
   pending_sync_data_.erase(id);
   synced_extensions_.insert(id);
 }
 
 }  // namespace extensions