[cronet] Add member for QUIC user agent ID, with getter and setter.

components/cronet/ios/cronet_environment.mm

 // Copyright 2016 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.
 
 #include "components/cronet/ios/cronet_environment.h"
 
 #include <utility>
 
 #include "base/at_exit.h"
 #include "base/atomicops.h"
@@ skipping 195 matching lines @@
                                     int port,
                                     int alternate_port) {
   DCHECK(port == alternate_port);
   quic_hints_.push_back(net::HostPortPair(host, port));
 }
 
 CronetEnvironment::CronetEnvironment(const std::string& user_agent,
                                      bool user_agent_partial)
     : http2_enabled_(false),
       quic_enabled_(false),
+      quic_user_agent_id_(""),

[mef, 2016/12/12 21:52:20]

std::string is initialized to empty string by default.

[lilyhoughton, 2016/12/13 15:10:22]

Done.

       user_agent_(user_agent),
       user_agent_partial_(user_agent_partial),
       net_log_(new net::NetLog) {}
 
 void CronetEnvironment::Start() {
   // Threads setup.
   network_cache_thread_.reset(new base::Thread("Chrome Network Cache Thread"));
   network_cache_thread_->StartWithOptions(
       base::Thread::Options(base::MessageLoop::TYPE_IO, 0));
   network_io_thread_.reset(new base::Thread("Chrome Network IO Thread"));
@@ skipping 38 matching lines @@
     user_agent_ = web::BuildUserAgentFromProduct(user_agent_);
 
   // Cache
   base::FilePath cache_path;
   if (!PathService::Get(base::DIR_CACHE, &cache_path))
     return;
   cache_path = cache_path.Append(FILE_PATH_LITERAL("cronet"));
 
   std::unique_ptr<URLRequestContextConfig> config(new URLRequestContextConfig(
       quic_enabled_,                  // Enable QUIC.
-      "",                             // QUIC User Agent ID.
+      quic_user_agent_id_,            // QUIC User Agent ID.

[mef, 2016/12/12 21:52:20]

could call getDefault... here if |quic_user_agent_id_| is empty.

[lilyhoughton, 2016/12/13 15:10:22]

It should also check if |quic_enabled_| is true, to avoid an unnecessary
NSBundle call, right?

[mef, 2016/12/13 20:46:43]

Yes, good point.

       http2_enabled_,                 // Enable SPDY.
       false,                          // Enable SDCH
       URLRequestContextConfig::DISK,  // Type of http cache.
       0,                              // Max size of http cache in bytes.
       false,                          // Disable caching for HTTP responses.
       cache_path.value(),  // Storage path for http cache and cookie storage.
       user_agent_,         // User-Agent request header field.
       "{}",                // JSON encoded experimental options.
       "",                  // Data reduction proxy key.
       "",                  // Data reduction proxy.
@@ skipping 67 matching lines @@
 
 void CronetEnvironment::SetHostResolverRulesOnNetworkThread(
     const std::string& rules,
     base::WaitableEvent* event) {
   static_cast<net::MappedHostResolver*>(main_context_->host_resolver())
       ->SetRulesFromString(rules);
   event->Signal();
 }
 
 }  // namespace cronet