[SafeBrowsing] Send pings for Zip files that contain other archives.

chrome/common/safe_browsing/csd.proto

 // Copyright (c) 2012 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 227 matching lines @@
   optional string file_basename = 9;
 
   // Starting with Chrome M19 we're also sending back pings for Chrome
   // extensions that get downloaded by users.
   enum DownloadType {
     WIN_EXECUTABLE = 0;    // Currently all .exe, .cab and .msi files.
     CHROME_EXTENSION = 1;  // .crx files.
     ANDROID_APK = 2;       // .apk files.
     // .zip files containing one of the other executable types.
     ZIPPED_EXECUTABLE = 3;
-    MAC_EXECUTABLE = 4;    // .dmg, .pkg, etc.
+    MAC_EXECUTABLE = 4;  // .dmg, .pkg, etc.
+    ZIPPED_ARCHIVE = 5;  // .zip file containing another archive.
   }
   optional DownloadType download_type = 10 [default = WIN_EXECUTABLE];
 
   // Locale of the device, eg en, en_US.
   optional string locale = 11;
 
   message PEImageHeaders {
     // IMAGE_DOS_HEADER.
     optional bytes dos_header = 1;
     // IMAGE_FILE_HEADER.
@@ skipping 286 matching lines @@
   message EnvironmentRequest { optional int32 dll_index = 1; }
 
   repeated EnvironmentRequest environment_requests = 3;
 }
 
 message DownloadMetadata {
   optional uint32 download_id = 1;
 
   optional ClientIncidentReport.DownloadDetails download = 2;
 }