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

components/safe_browsing_db/v4_protocol_manager_util.h

Index: components/safe_browsing_db/v4_protocol_manager_util.h
diff --git a/components/safe_browsing_db/v4_protocol_manager_util.h b/components/safe_browsing_db/v4_protocol_manager_util.h
index 882fb4a45cc993686ac8a829ba72cae56dd6dc29..1619fd5c298d601c7768fbc9c024870d9269f4dc 100644
--- a/components/safe_browsing_db/v4_protocol_manager_util.h
+++ b/components/safe_browsing_db/v4_protocol_manager_util.h
@@ -115,6 +115,9 @@ enum SBThreatType {
 
   // Activation patterns for the Subresource Filter.
   SB_THREAT_TYPE_SUBRESOURCE_FILTER,
+
+  // CSD Phishing whitelist.  This "threat" means a URL matched the whitelist.
+  SB_THREAT_TYPE_CSD_WHITELIST,
 };
 
 // The information required to uniquely identify each list the client is