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

ios/chrome/browser/signin/signin_client_impl.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/signin/signin_client_impl.h"
 
 #include <stddef.h>
 
 #include <utility>
 
@@ skipping 115 matching lines @@
   ios::HostContentSettingsMapFactory::GetForBrowserState(browser_state_)
       ->AddObserver(observer);
 }
 
 void SigninClientImpl::RemoveContentSettingsObserver(
     content_settings::Observer* observer) {
   ios::HostContentSettingsMapFactory::GetForBrowserState(browser_state_)
       ->RemoveObserver(observer);
 }
 
-scoped_ptr<SigninClient::CookieChangedSubscription>
+std::unique_ptr<SigninClient::CookieChangedSubscription>
 SigninClientImpl::AddCookieChangedCallback(
     const GURL& url,
     const std::string& name,
     const net::CookieStore::CookieChangedCallback& callback) {
   scoped_refptr<net::URLRequestContextGetter> context_getter =
       browser_state_->GetRequestContext();
   DCHECK(context_getter.get());
-  scoped_ptr<SigninCookieChangedSubscription> subscription(
+  std::unique_ptr<SigninCookieChangedSubscription> subscription(
       new SigninCookieChangedSubscription(context_getter, url, name, callback));
   return std::move(subscription);
 }
 
 void SigninClientImpl::OnSignedIn(const std::string& account_id,
                                   const std::string& gaia_id,
                                   const std::string& username,
                                   const std::string& password) {
   ios::ChromeBrowserStateManager* browser_state_manager =
       GetApplicationContext()->GetChromeBrowserStateManager();
@@ skipping 14 matching lines @@
   size_t index = cache->GetIndexOfBrowserStateWithPath(
       browser_state_->GetOriginalChromeBrowserState()->GetStatePath());
   if (index == std::string::npos)
     return;
 
   cache->SetBrowserStateIsAuthErrorAtIndex(
       index, signin_error_controller_->HasError());
 }
 
 void SigninClientImpl::OnGetTokenInfoResponse(
-    scoped_ptr<base::DictionaryValue> token_info) {
+    std::unique_ptr<base::DictionaryValue> token_info) {
   oauth_request_.reset();
 }
 
 void SigninClientImpl::OnOAuthError() {
   // Ignore the failure.  It's not essential and we'll try again next time.
   oauth_request_.reset();
 }
 
 void SigninClientImpl::OnNetworkError(int response_code) {
   // Ignore the failure.  It's not essential and we'll try again next time.
@@ skipping 40 matching lines @@
     callback.Run();
   }
 }
 
 GaiaAuthFetcher* SigninClientImpl::CreateGaiaAuthFetcher(
     GaiaAuthConsumer* consumer,
     const std::string& source,
     net::URLRequestContextGetter* getter) {
   return new GaiaAuthFetcherIOS(consumer, source, getter, browser_state_);
 }