Convert //ios from scoped_ptr to std::unique_ptr.

ios/chrome/browser/autocomplete/autocomplete_provider_client_impl.cc

 // 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/autocomplete/autocomplete_provider_client_impl.h"
 
 #include "base/strings/utf_string_conversions.h"
 #include "components/browser_sync/browser/profile_sync_service.h"
 #include "components/history/core/browser/history_service.h"
 #include "components/keyed_service/core/service_access_type.h"
@@ skipping 79 matching lines @@
 AutocompleteProviderClientImpl::GetShortcutsBackend() {
   return ios::ShortcutsBackendFactory::GetForBrowserState(browser_state_);
 }
 
 scoped_refptr<ShortcutsBackend>
 AutocompleteProviderClientImpl::GetShortcutsBackendIfExists() {
   return ios::ShortcutsBackendFactory::GetForBrowserStateIfExists(
       browser_state_);
 }
 
-scoped_ptr<KeywordExtensionsDelegate>
+std::unique_ptr<KeywordExtensionsDelegate>
 AutocompleteProviderClientImpl::GetKeywordExtensionsDelegate(
     KeywordProvider* keyword_provider) {
   return nullptr;
 }
 
 std::string AutocompleteProviderClientImpl::GetAcceptLanguages() const {
   return browser_state_->GetPrefs()->GetString(prefs::kAcceptLanguages);
 }
 
 std::string
@@ skipping 43 matching lines @@
     const base::string16& term) {
   GetHistoryService()->DeleteMatchingURLsForKeyword(keyword_id, term);
 }
 
 void AutocompleteProviderClientImpl::PrefetchImage(const GURL& url) {}
 
 void AutocompleteProviderClientImpl::OnAutocompleteControllerResultReady(
     AutocompleteController* controller) {
   // iOS currently has no client for this event.
 }