[Cronet] change InitializeOnNetworkThread to use URLRequestContextBuilder

components/cronet/ios/cronet_environment.h

Index: components/cronet/ios/cronet_environment.h
diff --git a/components/cronet/ios/cronet_environment.h b/components/cronet/ios/cronet_environment.h
index 6afde9cb6236346fda0a17db616f6ee6375e1e88..07b064a61da3b1a75a7cb844cf7417d699b21e82 100644
--- a/components/cronet/ios/cronet_environment.h
+++ b/components/cronet/ios/cronet_environment.h
@@ -16,7 +16,6 @@
 #include "base/threading/thread.h"
 #include "components/cronet/url_request_context_config.h"
 #include "net/cert/cert_verifier.h"
-#include "net/url_request/url_request.h"
 #include "net/url_request/url_request_context.h"
 #include "net/url_request/url_request_context_getter.h"
 
@@ -27,10 +26,8 @@ class WaitableEvent;
 }  // namespace base
 
 namespace net {
-class HttpCache;
 class NetworkChangeNotifier;
 class NetLog;
-class ProxyConfigService;
 class WriteToFileNetLogObserver;
 }  // namespace net
 
@@ -80,8 +77,9 @@ class CronetEnvironment {
     accept_language_ = accept_language;
   }
 
-  void set_cert_verifier(std::unique_ptr<net::CertVerifier> cert_verifier) {
-    cert_verifier_ = std::move(cert_verifier);
+  void set_mock_cert_verifier(
+      std::unique_ptr<net::CertVerifier> mock_cert_verifier) {
+    mock_cert_verifier_ = std::move(mock_cert_verifier);
   }
 
   void set_host_resolver_rules(const std::string& host_resolver_rules) {
@@ -133,10 +131,7 @@ class CronetEnvironment {
   std::unique_ptr<base::Thread> file_thread_;
   std::unique_ptr<base::Thread> file_user_blocking_thread_;
   scoped_refptr<base::SequencedTaskRunner> pref_store_worker_pool_;
-  scoped_refptr<JsonPrefStore> net_pref_store_;
-  std::unique_ptr<net::CertVerifier> cert_verifier_;
-  std::unique_ptr<net::ProxyConfigService> proxy_config_service_;
-  std::unique_ptr<net::HttpServerProperties> http_server_properties_;
+  std::unique_ptr<net::CertVerifier> mock_cert_verifier_;
   std::unique_ptr<net::URLRequestContext> main_context_;
   scoped_refptr<net::URLRequestContextGetter> main_context_getter_;
   std::string user_agent_;