Add the ability to check the CSD Whitelist asynchronously, for PhishGuard.

chrome/browser/safe_browsing/local_database_manager.cc

Index: chrome/browser/safe_browsing/local_database_manager.cc
diff --git a/chrome/browser/safe_browsing/local_database_manager.cc b/chrome/browser/safe_browsing/local_database_manager.cc
index 7c031ea1b74bac771a7409f13e3fbdb7e866d6a1..106f724939252ab97224a51dabd54c76853bcb9d 100644
--- a/chrome/browser/safe_browsing/local_database_manager.cc
+++ b/chrome/browser/safe_browsing/local_database_manager.cc
@@ -427,6 +427,14 @@ bool LocalSafeBrowsingDatabaseManager::MatchMalwareIP(
   return database_->ContainsMalwareIP(ip_address);
 }
 
+AsyncMatch LocalSafeBrowsingDatabaseManager::CheckCsdWhitelistUrl(
+    const GURL& url,
+    Client* Client) {
+  // Pver3 DB does not support actual partial-hash whitelists, so we emulate
+  // it.  All this code will go away soon (~M62).
+  return (MatchCsdWhitelistUrl(url) ? AsyncMatch::MATCH : AsyncMatch::NO_MATCH);
+}
+
 bool LocalSafeBrowsingDatabaseManager::MatchCsdWhitelistUrl(const GURL& url) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   if (!enabled_ || !enable_csd_whitelist_ || !MakeDatabaseAvailable()) {