Make iOS's IOThread set up the SystemURLRequestContext all at once.

ios/components/io_thread/ios_io_thread.mm

 // Copyright 2017 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 "ios/components/io_thread/ios_io_thread.h"
 
 #include <stddef.h>
 
 #include <utility>
 #include <vector>
@@ skipping 224 matching lines @@
 // dependencies and (2) make IOSIOThread more flexible for testing.
 IOSIOThread::IOSIOThread(PrefService* local_state,
                          net_log::ChromeNetLog* net_log)
     : net_log_(net_log),
       globals_(nullptr),
       creation_time_(base::TimeTicks::Now()),
       weak_factory_(this) {
   pref_proxy_config_tracker_ =
       ProxyServiceFactory::CreatePrefProxyConfigTrackerOfLocalState(
           local_state);
+  system_proxy_config_service_ = ProxyServiceFactory::CreateProxyConfigService(
+      pref_proxy_config_tracker_.get());
+
   ssl_config_service_manager_.reset(
       ssl_config::SSLConfigServiceManager::CreateDefaultManager(
           local_state,
           web::WebThread::GetTaskRunnerForThread(web::WebThread::IO)));
 
   web::WebThread::SetDelegate(web::WebThread::IO, this);
 }
 
 IOSIOThread::~IOSIOThread() {
   // This isn't needed for production code, but in tests, IOSIOThread may
@@ skipping 23 matching lines @@
   DCHECK_CURRENTLY_ON(web::WebThread::UI);
   web::WebThread::PostTask(
       web::WebThread::IO, FROM_HERE,
       base::Bind(&IOSIOThread::ChangedToOnTheRecordOnIOThread,
                  base::Unretained(this)));
 }
 
 net::URLRequestContextGetter* IOSIOThread::system_url_request_context_getter() {
   DCHECK_CURRENTLY_ON(web::WebThread::UI);
   if (!system_url_request_context_getter_.get()) {
-    InitSystemRequestContext();
+    // If we're in unit_tests, IOSIOThread may not be run.
+    if (!web::WebThread::IsMessageLoopValid(web::WebThread::IO))
+      return nullptr;
+    system_url_request_context_getter_ =
+        new SystemURLRequestContextGetter(this);
   }
   return system_url_request_context_getter_.get();
 }
 
 void IOSIOThread::Init() {
   TRACE_EVENT0("startup", "IOSIOThread::Init");
   DCHECK_CURRENTLY_ON(web::WebThread::IO);
 
   DCHECK(!globals_);
   globals_ = new Globals;
@@ skipping 47 matching lines @@
   quic_user_agent_id.append(
       version_info::GetProductNameAndVersionForUserAgent());
   quic_user_agent_id.push_back(' ');
   quic_user_agent_id.append(web::BuildOSCpuInfo());
 
   // Set up field trials, ignoring debug command line options.
   network_session_configurator::ParseCommandLineAndFieldTrials(
       base::CommandLine(base::CommandLine::NO_PROGRAM),
       /*is_quic_force_disabled=*/false, quic_user_agent_id, &params_);
 
-  // InitSystemRequestContext turns right around and posts a task back
-  // to the IO thread, so we can't let it run until we know the IO
-  // thread has started.
-  //
-  // Note that since we are at WebThread::Init time, the UI thread
-  // is blocked waiting for the thread to start.  Therefore, posting
-  // this task to the main thread's message loop here is guaranteed to
-  // get it onto the message loop while the IOSIOThread object still
-  // exists.  However, the message might not be processed on the UI
-  // thread until after IOSIOThread is gone, so use a weak pointer.
-  web::WebThread::PostTask(web::WebThread::UI, FROM_HERE,
-                           base::Bind(&IOSIOThread::InitSystemRequestContext,
-                                      weak_factory_.GetWeakPtr()));
+  globals_->system_proxy_service = ProxyServiceFactory::CreateProxyService(
+      net_log_, nullptr, globals_->system_network_delegate.get(),
+      std::move(system_proxy_config_service_), true /* quick_check_enabled */);
+
+  globals_->system_request_context.reset(
+      ConstructSystemRequestContext(globals_, params_, net_log_));
 }
 
 void IOSIOThread::CleanUp() {
   system_url_request_context_getter_->Shutdown();
   system_url_request_context_getter_ = nullptr;
 
   // Release objects that the net::URLRequestContext could have been pointing
   // to.
 
   // Shutdown the HistogramWatcher on the IO thread.
@@ skipping 43 matching lines @@
 }
 
 void IOSIOThread::ChangedToOnTheRecordOnIOThread() {
   DCHECK_CURRENTLY_ON(web::WebThread::IO);
 
   // Clear the host cache to avoid showing entries from the OTR session
   // in about:net-internals.
   ClearHostCache();
 }
 
-void IOSIOThread::InitSystemRequestContext() {
-  if (system_url_request_context_getter_.get())
-    return;
-  // If we're in unit_tests, IOSIOThread may not be run.
-  if (!web::WebThread::IsMessageLoopValid(web::WebThread::IO))
-    return;
-  system_proxy_config_service_ = ProxyServiceFactory::CreateProxyConfigService(
-      pref_proxy_config_tracker_.get());
-
-  system_url_request_context_getter_ = new SystemURLRequestContextGetter(this);
-  // Safe to post an unretained this pointer, since IOSIOThread is
-  // guaranteed to outlive the IO WebThread.
-  web::WebThread::PostTask(
-      web::WebThread::IO, FROM_HERE,
-      base::Bind(&IOSIOThread::InitSystemRequestContextOnIOThread,
-                 base::Unretained(this)));
-}
-
-void IOSIOThread::InitSystemRequestContextOnIOThread() {
-  DCHECK_CURRENTLY_ON(web::WebThread::IO);
-  DCHECK(!globals_->system_proxy_service.get());
-  DCHECK(system_proxy_config_service_.get());
-
-  globals_->system_proxy_service = ProxyServiceFactory::CreateProxyService(
-      net_log_, nullptr, globals_->system_network_delegate.get(),
-      std::move(system_proxy_config_service_), true /* quick_check_enabled */);
-
-  globals_->system_request_context.reset(
-      ConstructSystemRequestContext(globals_, params_, net_log_));
-}
-
 net::URLRequestContext* IOSIOThread::ConstructSystemRequestContext(
     IOSIOThread::Globals* globals,
     const net::HttpNetworkSession::Params& params,
     net::NetLog* net_log) {
   net::URLRequestContext* context = new SystemURLRequestContext;
   context->set_net_log(net_log);
   context->set_host_resolver(globals->host_resolver.get());
   context->set_cert_verifier(globals->cert_verifier.get());
   context->set_transport_security_state(
       globals->transport_security_state.get());
@@ skipping 31 matching lines @@
       new net::HttpNetworkSession(params, system_context));
   globals->system_http_transaction_factory.reset(
       new net::HttpNetworkLayer(globals->system_http_network_session.get()));
   context->set_http_transaction_factory(
       globals->system_http_transaction_factory.get());
 
   return context;
 }
 
 }  // namespace io_thread