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

ios/components/io_thread/ios_io_thread.h

 // 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.
 
 #ifndef IOS_COMPONENTS_IO_THREAD_IOS_IO_THREAD_H_
 #define IOS_COMPONENTS_IO_THREAD_IOS_IO_THREAD_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 159 matching lines @@
   // Provide SystemURLRequestContextGetter with access to
   // InitSystemRequestContext().
   friend class SystemURLRequestContextGetter;
 
   // WebThreadDelegate implementation, runs on the IO thread.
   // This handles initialization and destruction of state that must
   // live on the IO thread.
   void Init() override;
   void CleanUp() override;
 
-  // Global state must be initialized on the IO thread, then this
-  // method must be invoked on the UI thread.
-  void InitSystemRequestContext();
-
-  // Lazy initialization of system request context for
-  // SystemURLRequestContextGetter. To be called on IO thread only
-  // after global state has been initialized on the IO thread, and
-  // SystemRequestContext state has been initialized on the UI thread.
-  void InitSystemRequestContextOnIOThread();
-
   // Sets up HttpAuthPreferences and HttpAuthHandlerFactory on Globals.
   void CreateDefaultAuthHandlerFactory();
 
   // Returns an SSLConfigService instance.
   net::SSLConfigService* GetSSLConfigService();
 
   // Discards confidental data. To be called on IO thread only.
   void ChangedToOnTheRecordOnIOThread();
 
   static net::URLRequestContext* ConstructSystemRequestContext(
@@ skipping 38 matching lines @@
   const base::TimeTicks creation_time_;
 
   base::WeakPtrFactory<IOSIOThread> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(IOSIOThread);
 };
 
 }  // namespace io_thread
 
 #endif  // IOS_COMPONENTS_IO_THREAD_IO_THREAD_H_