[ObjC ARC] Converts ios/chrome/browser/ui/first_run:first_run to ARC.

ios/chrome/browser/ui/first_run/first_run_util.mm

 // Copyright 2014 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.
 
 #import "ios/chrome/browser/ui/first_run/first_run_util.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/time/time.h"
 #include "components/signin/core/browser/signin_manager.h"
 #include "ios/chrome/browser/browser_state/chrome_browser_state.h"
 #import "ios/chrome/browser/crash_report/breakpad_helper.h"
 #include "ios/chrome/browser/first_run/first_run.h"
 #import "ios/chrome/browser/first_run/first_run_configuration.h"
 #include "ios/chrome/browser/first_run/first_run_metrics.h"
 #include "ios/chrome/browser/signin/signin_manager_factory.h"
 #include "ios/chrome/browser/tabs/tab.h"
 #include "ios/chrome/browser/ui/first_run/first_run_histograms.h"
 #import "ios/chrome/browser/ui/settings/settings_utils.h"
 #import "ios/chrome/browser/ui/sync/sync_util.h"
 #include "ios/chrome/browser/ui/ui_util.h"
 #include "ios/web/public/web_thread.h"
 #import "ui/gfx/ios/NSString+CrStringDrawing.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 NSString* const kChromeFirstRunUIWillFinishNotification =
     @"kChromeFirstRunUIWillFinishNotification";
 
 NSString* const kChromeFirstRunUIDidFinishNotification =
     @"kChromeFirstRunUIDidFinishNotification";
 
 namespace {
 
 NSString* RemoveLastWord(NSString* text) {
   __block NSRange range = NSMakeRange(0, [text length]);
@@ skipping 22 matching lines @@
                                        NSStringEnumerationSubstringNotRequired;
   [text
       enumerateSubstringsInRange:range
                          options:options
                       usingBlock:^(NSString* substring, NSRange substringRange,
                                    NSRange enclosingRange, BOOL* stop) {
                         range = substringRange;
                         count++;
                         *stop = count == index;
                       }];
-  NSMutableString* textWithNewline = [[text mutableCopy] autorelease];
+  NSMutableString* textWithNewline = [text mutableCopy];
   [textWithNewline insertString:@"\n" atIndex:range.location];
   return textWithNewline;
 }
 
 // Trampoline method for Bind to create the sentinel file.
 bool CreateSentinel() {
   return FirstRun::CreateSentinel();
 }
 
 // Helper function for recording first run metrics. Takes an additional
@@ skipping 98 matching lines @@
                                        base::TimeDelta::FromMinutes(3), 50);
 }
 
 void FirstRunDismissed() {
   [[NSNotificationCenter defaultCenter]
       postNotificationName:kChromeFirstRunUIDidFinishNotification
                     object:nil];
 }
 
 }  // namespace ios_internal