[ObjC ARC] Converts components/translate/ios/browser:browser to ARC.

components/translate/ios/browser/js_translate_manager.mm

 // Copyright 2013 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 "components/translate/ios/browser/js_translate_manager.h"
 
 #import <Foundation/Foundation.h>
 
 #include <memory>
 
 #include "base/logging.h"
 #include "base/mac/bundle_locations.h"
-#import "base/mac/scoped_nsobject.h"
+#import "ios/web/public/web_state/js/crw_js_injection_receiver.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
 
 @implementation JsTranslateManager {
-  base::scoped_nsobject<NSString> _translationScript;
+  NSString* _translationScript;
 }
 
 - (NSString*)script {
-  return _translationScript.get();
+  return _translationScript;
 }
 
 - (void)setScript:(NSString*)script {
   // The translation script uses performance.now() for metrics, which is not
   // supported except on iOS 8.0. To make the translation script work on these
   // iOS versions, add some JavaScript to |script| that defines an
   // implementation of performance.now().
   NSString* const kPerformancePlaceholder =
       @"var performance = window['performance'] || {};"
       @"performance.now = performance['now'] ||"
       @"(function () { return Date.now(); });\n";
   script = [kPerformancePlaceholder stringByAppendingString:script];
   // TODO(shreyasv): This leads to some duplicate code from
   // CRWJSInjectionManager. Consider refactoring this to its own js injection
   // manager.
   NSString* path =
       [base::mac::FrameworkBundle() pathForResource:@"translate_ios"
                                              ofType:@"js"];
   DCHECK(path);
   NSError* error = nil;
   NSString* content = [NSString stringWithContentsOfFile:path
                                                 encoding:NSUTF8StringEncoding
                                                    error:&error];
   DCHECK(!error && [content length]);
   script = [script stringByAppendingString:content];
-  _translationScript.reset([script copy]);
+  _translationScript = [script copy];
 }
 
 - (void)injectWaitUntilTranslateReadyScript {
   [self.receiver executeJavaScript:@"__gCrWeb.translate.checkTranslateReady()"
                  completionHandler:nil];
 }
 
 - (void)injectTranslateStatusScript {
   [self.receiver executeJavaScript:@"__gCrWeb.translate.checkTranslateStatus()"
                  completionHandler:nil];
@@ skipping 11 matching lines @@
   DCHECK([self hasBeenInjected]);
   [self.receiver executeJavaScript:@"cr.googleTranslate.revert()"
                  completionHandler:nil];
 }
 
 #pragma mark -
 #pragma mark CRWJSInjectionManager methods
 
 - (NSString*)injectionContent {
   DCHECK(_translationScript);
-  return _translationScript.autorelease();
+  NSString* translationScript = _translationScript;
+  _translationScript = nil;
+  return translationScript;
 }
 
 @end