Parse the whitelist expressions from the phishing verdict response if

chrome/common/safe_browsing/csd.proto

 // 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.
 //
 // Client side phishing and malware detection request and response
 // protocol buffers.  Those protocol messages should be kept in sync
 // with the server implementation.
 //
 // If you want to change this protocol definition or you have questions
 // regarding its format please contact chrome-anti-phishing@googlegroups.com.
@@ skipping 49 matching lines @@
   repeated Feature non_model_feature_map = 8;
 
   // The referrer URL.  This field might not be set, for example, in the case
   // where the referrer uses HTTPs.
   // OBSOLETE: Use feature 'Referrer=<referrer>' instead.
   optional string OBSOLETE_referrer_url = 9;
 }
 
 message ClientPhishingResponse {
   required bool phishy = 1;
+
+  // A list of SafeBrowsing host-suffix / path-prefix expressions that
+  // are whitelisted.  The client must match the current top-level URL
+  // against these whitelisted expressions and only apply a positive
+  // phishing verdict above if the URL does not match any expression
+  // on this whitelist.  The client must not cache these whitelisted
+  // expressions.  This whitelist will be empty for the vast majority
+  // of the responses but might contain up to 100 entries in emergency
+  // situations.
+  repeated string whitelist_expression = 2;
 }