Moving gRPC support interfaces out of cronet and into a new component.

components/cronet/ios/cronet_environment.cc

 // 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 49 matching lines @@
 
 base::AtExitManager* g_at_exit_ = nullptr;
 net::NetworkChangeNotifier* g_network_change_notifier = nullptr;
 // MessageLoop on the main thread.
 base::MessageLoop* g_main_message_loop = nullptr;
 
 }  // namespace
 
 namespace cronet {
 
-bool CronetEnvironment::IsOnNetworkThread() {
-  return network_io_thread_->task_runner()->BelongsToCurrentThread();
-}
-
 void CronetEnvironment::PostToNetworkThread(
     const tracked_objects::Location& from_here,
     const base::Closure& task) {
   network_io_thread_->task_runner()->PostTask(from_here, task);
 }
 
 void CronetEnvironment::PostToFileUserBlockingThread(
     const tracked_objects::Location& from_here,
     const base::Closure& task) {
   file_user_blocking_thread_->task_runner()->PostTask(from_here, task);
 }
 
-net::URLRequestContext* CronetEnvironment::GetURLRequestContext() const {
-  return main_context_.get();
+net::URLRequestContextGetter* CronetEnvironment::GetURLRequestContextGetter() {
+  return request_context_getter_.get();
 }
 
 // static
 void CronetEnvironment::Initialize() {
   // DCHECK_EQ([NSThread currentThread], [NSThread mainThread]);
   // This method must be called once from the main thread.
   if (!g_at_exit_)
     g_at_exit_ = new base::AtExitManager;
 
   url::Initialize();
@@ skipping 118 matching lines @@
     if (!PathService::Get(base::DIR_HOME, &ssl_key_log_file))
       return;
     net::SSLClientSocket::SetSSLKeyLogFile(
         ssl_key_log_file.Append(ssl_key_log_file_name_),
         file_thread_->task_runner());
   }
 
   proxy_config_service_ = net::ProxyService::CreateSystemProxyConfigService(
       network_io_thread_->task_runner(), nullptr);
 
+  // Create request_context_getter_ here so that it will be availble as soon

[mef, 2016/10/11 22:09:37]

Would it be easier to have custom net::URLRequestContextGetter which is aware of
CronetEnvironment like in
https://codereview.chromium.org/2146643002/diff/420001/components/cronet/ios/...

[Garrett Casto, 2016/10/12 00:23:36]

Yes. If nothing else this doesn't require getting approval to add
DetachFromThread to URLRequestContext, which seems like a win.

+  // as this function returns. main_context_ won't actually be setup at that
+  // point, but any usage should happen on the network thread and the
+  // initialization callback will be run before any other posted task.
+  main_context_.reset(new net::URLRequestContext);
+  main_context_->DetachFromThread();
+  request_context_getter_ = new net::TrivialURLRequestContextGetter(
+      main_context_.get(), network_io_thread_->task_runner());
+
 #if defined(USE_NSS_CERTS)
   net::SetURLRequestContextForNSSHttpIO(main_context_.get());
 #endif
   base::subtle::MemoryBarrier();
   PostToNetworkThread(FROM_HERE,
                       base::Bind(&CronetEnvironment::InitializeOnNetworkThread,
                                  base::Unretained(this)));
 }
 
 CronetEnvironment::~CronetEnvironment() {
 // net::HTTPProtocolHandlerDelegate::SetInstance(nullptr);
 #if defined(USE_NSS_CERTS)
   net::SetURLRequestContextForNSSHttpIO(nullptr);
 #endif
 }
 
 void CronetEnvironment::InitializeOnNetworkThread() {
   DCHECK(network_io_thread_->task_runner()->BelongsToCurrentThread());
   base::FeatureList::InitializeInstance(std::string(), std::string());
   // TODO(mef): Use net:UrlRequestContextBuilder instead of manual build.
-  main_context_.reset(new net::URLRequestContext);
   main_context_->set_net_log(net_log_.get());
   std::string user_agent(user_agent_product_name_ +
                          " (iOS); Cronet/" CRONET_VERSION);
   main_context_->set_http_user_agent_settings(
       new net::StaticHttpUserAgentSettings("en", user_agent));
 
   main_context_->set_ssl_config_service(new net::SSLConfigServiceDefaults);
   main_context_->set_transport_security_state(
       new net::TransportSecurityState());
   http_server_properties_.reset(new net::HttpServerPropertiesImpl());
@@ skipping 96 matching lines @@
   const net::HttpUserAgentSettings* user_agent_settings =
       main_context_->http_user_agent_settings();
   if (!user_agent_settings) {
     return nullptr;
   }
 
   return user_agent_settings->GetUserAgent();
 }
 
 }  // namespace cronet