Convert //ios/web_view/internal to ARC.

ios/web_view/internal/criwv.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/web_view/public/criwv.h"
 
 #include <memory>
 
 #include "base/location.h"
 #import "base/mac/bind_objc_block.h"
 #include "base/single_thread_task_runner.h"
 #include "ios/web/public/app/web_main.h"
 #include "ios/web/public/web_thread.h"
 #import "ios/web_view/internal/criwv_web_main_delegate.h"
 #import "ios/web_view/public/criwv_delegate.h"
 #import "ios/web_view/public/criwv_web_view.h"
 #import "ios/web_view/public/criwv_web_view_configuration.h"
 #import "ios/web_view/public/criwv_website_data_store.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 CRIWV* g_criwv = nil;
 }
 
 @interface CRIWV () {
-  id<CRIWVDelegate> _delegate;
+  __unsafe_unretained id<CRIWVDelegate> _delegate;

[Eugene But (OOO till 7-30), 2017/02/10 23:07:22]

Should this be __weak?

[michaeldo, 2017/02/11 06:02:32]

I was basing this off the arc migrate instructions, but yes, __weak I believe is
what we want here. Updated.

Stepan, please confirm.

   std::unique_ptr<ios_web_view::CRIWVWebMainDelegate> _webMainDelegate;
   std::unique_ptr<web::WebMain> _webMain;
 }
 
 - (instancetype)initWithDelegate:(id<CRIWVDelegate>)delegate;
 @end
 
 @implementation CRIWV
 
 + (void)configureWithDelegate:(id<CRIWVDelegate>)delegate {
   g_criwv = [[CRIWV alloc] initWithDelegate:delegate];
 }
 
 + (void)shutDown {
-  [g_criwv release];
   g_criwv = nil;
 }
 
 + (CRIWVWebView*)webViewWithFrame:(CGRect)frame {
   CRIWVWebViewConfiguration* configuration =
       [[CRIWVWebViewConfiguration alloc] init];
   configuration.websiteDataStore = [CRIWVWebsiteDataStore defaultDataStore];
 
-  return [[[CRIWVWebView alloc] initWithFrame:frame configuration:configuration]
-      autorelease];
+  return [[CRIWVWebView alloc] initWithFrame:frame configuration:configuration];
 }
 
 - (instancetype)initWithDelegate:(id<CRIWVDelegate>)delegate {
   self = [super init];
   if (self) {
     _delegate = delegate;
     _webMainDelegate.reset(new ios_web_view::CRIWVWebMainDelegate(_delegate));
     web::WebMainParams params(_webMainDelegate.get());
     _webMain.reset(new web::WebMain(params));
   }
   return self;
 }
 
 - (void)dealloc {
   _webMain.reset();
   _webMainDelegate.reset();
-  [super dealloc];
 }
 
 @end