Use copies of canned browsing data helpers to populate the cookies tree model.

chrome/browser/browsing_data_database_helper.cc

Index: chrome/browser/browsing_data_database_helper.cc
diff --git a/chrome/browser/browsing_data_database_helper.cc b/chrome/browser/browsing_data_database_helper.cc
index 68d1bbc8693bb29b8d12e0af9d13986d312cc8b9..1486b5a403c70ebeba4013d3a6b82276f8ad305c 100644
--- a/chrome/browser/browsing_data_database_helper.cc
+++ b/chrome/browser/browsing_data_database_helper.cc
@@ -157,7 +157,19 @@ CannedBrowsingDataDatabaseHelper::PendingDatabaseInfo::~PendingDatabaseInfo() {}
 
 CannedBrowsingDataDatabaseHelper::CannedBrowsingDataDatabaseHelper(
     Profile* profile)
-    : BrowsingDataDatabaseHelper(profile) {
+    : BrowsingDataDatabaseHelper(profile),
+      profile_(profile) {
+}
+
+CannedBrowsingDataDatabaseHelper* CannedBrowsingDataDatabaseHelper::Clone() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  CannedBrowsingDataDatabaseHelper* clone =
+      new CannedBrowsingDataDatabaseHelper(profile_);
+
+  base::AutoLock auto_lock(lock_);
+  clone->pending_database_info_ = pending_database_info_;
+  clone->database_info_ = database_info_;
+  return clone;
 }
 
 void CannedBrowsingDataDatabaseHelper::AddDatabase(