Change the client-side phishing detection hashing function to

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.
 
 syntax = "proto2";
 
 option optimize_for = LITE_RUNTIME;
 
 package safe_browsing;
 
 message ClientPhishingRequest {
   // URL that the client visited.  The CGI parameters are stripped by the
   // client.  This field is ONLY set for UMA-enabled users.
   optional string url = 1;
 
-  // A 5-byte SHA-256 hash prefix of the URL, in SafeBrowsing host sufffix/path
-  // prefix form with query parameters stripped (i.e. "www.example.com/1/2/").
+  // A 5-byte SHA-256 hash prefix of the URL.  Before hashing the URL is
+  // canonicalized, converted to a suffix-prefix expression and broadened
+  // (www prefix is removed and everything past the last '/' is stripped).
   // Unlike "url", this is sent for all users.
-  optional bytes suffix_prefix_hash = 10;
+  optional bytes hash_prefix = 10;
 
   // Score that was computed on the client.  Value is between 0.0 and 1.0.
   // The larger the value the more likely the url is phishing.
   required float client_score = 2;
 
   // Note: we're skipping tag 3 because it was previously used.
 
   // Is true if the features for this URL were classified as phishing.
   // Currently, this will always be true for all client-phishing requests
   // that are sent to the server.
@@ skipping 24 matching lines @@
 
   // 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;
 }