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

ios/chrome/browser/ui/preload_controller.mm

 // Copyright 2012 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 <UIKit/UIKit.h>
 
 #include "ios/chrome/browser/ui/preload_controller.h"
 
 #include "base/ios/device_util.h"
 #include "base/logging.h"
-#include "base/mac/scoped_nsobject.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/strings/sys_string_conversions.h"
 #include "components/prefs/pref_service.h"
 #include "ios/chrome/browser/browser_state/chrome_browser_state.h"
 #include "ios/chrome/browser/pref_names.h"
 #import "ios/chrome/browser/tabs/legacy_tab_helper.h"
 #import "ios/chrome/browser/tabs/tab.h"
 #import "ios/chrome/browser/tabs/tab_helper_util.h"
 #import "ios/chrome/browser/tabs/tab_private.h"
 #include "ios/chrome/browser/ui/preload_controller_delegate.h"
 #include "ios/chrome/browser/ui/prerender_final_status.h"
 #import "ios/web/public/web_state/ui/crw_native_content.h"
 #include "ios/web/public/web_thread.h"
 #import "ios/web/web_state/ui/crw_web_controller.h"
 #import "net/base/mac/url_conversions.h"
 #include "net/url_request/url_fetcher.h"
 #include "net/url_request/url_fetcher_delegate.h"
 #include "ui/base/page_transition_types.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 // ID of the URLFetcher responsible for prefetches.
 const int kPreloadControllerURLFetcherID = 1;
 
 namespace {
 // Delay before starting to prerender a URL.
 const NSTimeInterval kPrerenderDelay = 0.5;
 
 // The finch experiment to turn off prefetching as a field trial.
 const char kTabEvictionFieldTrialName[] = "TabEviction";
 // The associated group.
@@ skipping 53 matching lines @@
 
 // Delegate to handle completion of URLFetcher operations.
 class PrefetchDelegate : public net::URLFetcherDelegate {
  public:
   explicit PrefetchDelegate(PreloadController* owner) : owner_(owner) {}
   void OnURLFetchComplete(const net::URLFetcher* source) override {
     [owner_ prefetchDidComplete:source];
   }
 
  private:
-  PreloadController* owner_;  // weak
+  __weak PreloadController* owner_;
 };
 
 @implementation PreloadController {
   ios::ChromeBrowserState* browserState_;  // Weak.
 
   // The WebState used for prerendering.
   std::unique_ptr<web::WebState> webState_;
 
   // The URL that is prerendered in |webState_|.  This can be different from
   // the value returned by WebState last committed navigation item, for example
@@ skipping 33 matching lines @@
   // Whether or not the preference is enabled.
   BOOL enabled_;
   // Whether or not prerendering is only when on wifi.
   BOOL wifiOnly_;
   // Whether or not the current connection is using WWAN.
   BOOL usingWWAN_;
 
   // Number of successful prerenders (i.e. the user viewed the prerendered page)
   // during the lifetime of this controller.
   int successfulPrerendersPerSessionCount_;
-
-  id<PreloadControllerDelegate> delegate_;  // weak
 }
 
 @synthesize prerenderedURL = prerenderedURL_;
 @synthesize prefetchedURL = prefetchedURL_;
 @synthesize delegate = delegate_;
 
 - (instancetype)initWithBrowserState:(ios::ChromeBrowserState*)browserState {
   DCHECK(browserState);
   DCHECK_CURRENTLY_ON(web::WebThread::UI);
   if ((self = [super init])) {
@@ skipping 27 matching lines @@
 - (void)browserStateDestroyed {
   [self cancelPrerender];
   connectionTypeObserverBridge_.reset();
 }
 
 - (void)dealloc {
   UMA_HISTOGRAM_COUNTS(kPrerendersPerSessionCountHistogramName,
                        successfulPrerendersPerSessionCount_);
   [[NSNotificationCenter defaultCenter] removeObserver:self];
   [self cancelPrerender];
-  [super dealloc];
 }
 
 - (void)prerenderURL:(const GURL&)url
             referrer:(const web::Referrer&)referrer
           transition:(ui::PageTransition)transition
          immediately:(BOOL)immediately {
   // TODO(rohitrao): If shouldPrerenderURL returns false, should we cancel any
   // scheduled prerender requests?
   if (![self isPrerenderingEnabled] || ![self shouldPreloadURL:url])
     return;
@@ skipping 257 matching lines @@
   scheduledURL_ = GURL();
 }
 
 #pragma mark - TabDelegate
 
 - (void)discardPrerender {
   [self schedulePrerenderCancel];
 }
 
 @end