[ObjC ARC] Converts ios/chrome/browser/browser_state:browser_state_impl.

ios/chrome/browser/browser_state/chrome_browser_state_impl_io_data.mm

 // Copyright 2015 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/chrome/browser/browser_state/chrome_browser_state_impl_io_data.h"
 
 #include <memory>
 #include <set>
 #include <utility>
 
@@ skipping 26 matching lines @@
 #include "net/extras/sqlite/sqlite_channel_id_store.h"
 #include "net/http/http_cache.h"
 #include "net/http/http_network_session.h"
 #include "net/http/http_server_properties_manager.h"
 #include "net/sdch/sdch_owner.h"
 #include "net/ssl/channel_id_service.h"
 #include "net/ssl/default_channel_id_store.h"
 #include "net/url_request/url_request_intercepting_job_factory.h"
 #include "net/url_request/url_request_job_factory_impl.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 
 // Connects the SdchOwner's storage to the prefs.
 class SdchOwnerPrefStorage : public net::SdchOwner::PrefStorage,
                              public PrefStore::Observer {
  public:
   explicit SdchOwnerPrefStorage(PersistentPrefStore* storage)
       : storage_(storage), storage_key_("SDCH"), init_observer_(nullptr) {}
   ~SdchOwnerPrefStorage() override {
     if (init_observer_)
@@ skipping 418 matching lines @@
     const base::Closure& completion) {
   DCHECK_CURRENTLY_ON(web::WebThread::IO);
   DCHECK(initialized());
 
   DCHECK(transport_security_state());
   // Completes synchronously.
   transport_security_state()->DeleteAllDynamicDataSince(time);
   DCHECK(http_server_properties_manager_);
   http_server_properties_manager_->Clear(completion);
 }