Delete TLS version fallback code in net/http.

chrome/browser/resources/net_internals/log_view_painter.js

 // 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.
 
 // TODO(eroman): put these methods into a namespace.
 
 var createLogEntryTablePrinter;
 var proxySettingsToString;
 var stripPrivacyInfo;
 
@@ skipping 271 matching lines @@
       return writeParamsForRequestHeaders;
 
     case EventType.PROXY_CONFIG_CHANGED:
       return writeParamsForProxyConfigChanged;
 
     case EventType.CERT_VERIFIER_JOB:
     case EventType.SSL_CERTIFICATES_RECEIVED:
       return writeParamsForCertificates;
     case EventType.EV_CERT_CT_COMPLIANCE_CHECKED:
       return writeParamsForCheckedEVCertificates;
-
-    case EventType.SSL_VERSION_FALLBACK:
-      return writeParamsForSSLVersionFallback;
   }
   return null;
 }
 
 /**
  * Default parameter writer that outputs a visualization of field named |key|
  * with value |value| to |out|.
  */
 function defaultWriteParameter(key, value, out) {
   if (key == 'headers' && value instanceof Array) {
@@ skipping 95 matching lines @@
   if (matchingFlagNames.length == 0)
     return zeroName;
 
   return matchingFlagNames.join(' | ');
 }
 
 /**
  * Converts an SSL version number to a textual representation.
  * For instance, SSLVersionNumberToName(0x0301) returns 'TLS 1.0'.
  */
 function SSLVersionNumberToName(version) {

[eroman, 2016/06/24 19:19:44]

If you are going to delete the specific formatter code for fallback you should
delete this too.

That said, I would suggest not making changes to the file and instead adding a
TODO by the handler for SSL_VERSION_FALLBACK, indicating that it is deprecated
and a milestone for deleting the code -- say M56.

[davidben, 2016/06/24 19:26:18]

Done. I put it in the event list since it seems I need to keep that or the tests
get unhappy.

[eroman, 2016/06/24 19:42:00]

Actually I was envisioning the deprecation solely in the JS, and you would still
delete everything from C++.

Concretely:
  (a) Go ahead and delete the event from the net_log_event_list.h

  (b) Add a TODO in log_view_painter.js indicating the functionality was removed
from logs in XXX and to remove the code for handling it in YYY.

  (c) Hack the unit-test for SSL_VERSION_FALLBACK painting so it passes, or just
remove it. I expect you can hack it by adding a single line (and accompanying
TODO):

function painterTestSSLVersionFallback() {

  // TODO(eroman): Hack bla bla bla. Remove bla bla bla.
  EventType.SSL_VERSION_FALLBACK = 96793;

  <test code as before>
}

The issue is these run as browser tests and use whatever the current constants
are (which came from current C++).

We are in the process of splitting this code and tests out of Chrome anyway so
this will necessarily be changing soon. I would be OK with the above hack, and
it can be cleaned up when the tests are transitioned to their new reality.

[davidben, 2016/06/27 19:27:44]

From talking offline, it seems there were all kinds of screwiness around this
file where it didn't handle missing keys right (or relied on JavaScript's
behavior around undefined to do so). Would you still prefer I delete the event
from net_log_event_list.h or shall I leave the CL as it is?

[eroman, 2016/06/27 19:31:28]

Up to you, I don't feel too strongly about it.

[davidben, 2016/06/27 19:38:48]

Alright. I'll go land this as-is then and then assume you all will sort out the
painter later. :-)

Besides, perhaps I'll resurrect it for TLS 1.3 first anyway.

   if ((version & 0xFFFF) != version) {
     // If the version number is more than 2 bytes long something is wrong.
     // Print it as hex.
     return 'SSL 0x' + version.toString(16);
   }
 
   // See if it is a known TLS name.
   var kTLSNames = {
     0x0301: 'TLS 1.0',
     0x0302: 'TLS 1.1',
@@ skipping 228 matching lines @@
   }
 
 }
 
 function writeParamsForCheckedEVCertificates(entry, out, consumedParams) {
   if (typeof(entry.params.certificate) == 'object')
     writeCertificateParam(
         entry.params.certificate, out, consumedParams, 'certificate');
 }
 
-/**
- * Outputs the SSL version fallback parameters of |entry| to |out|.
- */
-function writeParamsForSSLVersionFallback(entry, out, consumedParams) {
-  var params = entry.params;
-
-  if (typeof params.version_before != 'number' ||
-      typeof params.version_after != 'number') {
-    // Unrecognized params.
-    return;
-  }
-
-  var line = SSLVersionNumberToName(params.version_before) +
-             ' ==> ' +
-             SSLVersionNumberToName(params.version_after);
-  out.writeArrowIndentedLines([line]);
-
-  consumedParams.version_before = true;
-  consumedParams.version_after = true;
-}
-
 function writeParamsForProxyConfigChanged(entry, out, consumedParams) {
   var params = entry.params;
 
   if (typeof params.new_config != 'object') {
     // Unrecognized params.
     return;
   }
 
   if (typeof params.old_config == 'object') {
     var oldConfigString = proxySettingsToString(params.old_config);
@@ skipping 112 matching lines @@
   }
 
   if (config.source != undefined && config.source != 'UNKNOWN')
     result.push('Source: ' + config.source);
 
   return result.join('\n');
 };
 
 // End of anonymous namespace.
 })();