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

ios/chrome/browser/ui/history/tab_history_view_controller.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/history/tab_history_view_controller.h"
 
 #import "base/ios/weak_nsobject.h"
 #include "base/logging.h"
 #include "base/mac/foundation_util.h"
-#include "base/mac/objc_property_releaser.h"
 #include "base/mac/scoped_nsobject.h"
 #include "base/strings/sys_string_conversions.h"
 #import "ios/chrome/browser/ui/commands/UIKit+ChromeExecuteCommand.h"
 #include "ios/chrome/browser/ui/commands/ios_command_ids.h"
 #import "ios/chrome/browser/ui/history/tab_history_cell.h"
 #include "ios/chrome/browser/ui/rtl_geometry.h"
 #import "ios/third_party/material_components_ios/src/components/Ink/src/MaterialInk.h"
 #import "ios/web/navigation/crw_session_entry.h"
 #include "ios/web/public/favicon_status.h"
 #include "ios/web/public/navigation_item.h"
 #include "ui/gfx/image/image.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 
 // Visible percentage of the last visible row on the Tools menu if the
 // Tools menu is scrollable.
 const CGFloat kLastRowVisiblePercentage = 0.6;
 // Reuse identifier for cells.
 NSString* cellIdentifier = @"TabHistoryCell";
 NSString* footerIdentifier = @"Footer";
 NSString* headerIdentifier = @"Header";
 // Height of rows.
@@ skipping 186 matching lines @@
 @interface TabHistoryViewController ()<MDCInkTouchControllerDelegate> {
   base::scoped_nsobject<MDCInkTouchController> _inkTouchController;
   base::scoped_nsobject<NSArray> _partitionedEntries;
   base::scoped_nsobject<NSArray> _sessionEntries;
 }
 @end
 
 @implementation TabHistoryViewController
 
 - (NSArray*)sessionEntries {
-  return [[_sessionEntries retain] autorelease];
+  return _sessionEntries;
 }
 
 #pragma mark Public Methods
 
 - (CGFloat)optimalHeight:(CGFloat)suggestedHeight {
   DCHECK(suggestedHeight >= kCellHeight);
   CGFloat optimalHeight = 0;
 
   for (NSArray* sectionArray in _partitionedEntries.get()) {
     NSUInteger sectionItemCount = [sectionArray count];
@@ skipping 123 matching lines @@
     iconImage = image.ToUIImage();
   else
     iconImage = [UIImage imageNamed:@"default_favicon"];
 
   [[header iconView] setImage:iconImage];
 
   return header;
 }
 
 - (void)setSessionEntries:(NSArray*)sessionEntries {
-  _sessionEntries.reset([sessionEntries retain]);
+  _sessionEntries.reset(sessionEntries);
 
   std::string previousHost;
 
   NSMutableArray* sectionArray = [NSMutableArray array];
   NSMutableArray* partitionedEntries = [NSMutableArray array];
 
   NSInteger numberOfEntries = [_sessionEntries count];
   for (NSInteger index = 0; index < numberOfEntries; ++index) {
     CRWSessionEntry* sessionEntry = [_sessionEntries objectAtIndex:index];
     web::NavigationItem* navigationItem = [sessionEntry navigationItem];
@@ skipping 15 matching lines @@
       previousHost = currentHost;
     }
   }
 
   if ([sectionArray count])
     [partitionedEntries addObject:sectionArray];
 
   if (![partitionedEntries count])
     partitionedEntries = nil;
 
-  _partitionedEntries.reset([partitionedEntries retain]);
+  _partitionedEntries.reset(partitionedEntries);
 }
 
 #pragma mark MDCInkTouchControllerDelegate
 
 - (BOOL)inkTouchController:(MDCInkTouchController*)inkTouchController
     shouldProcessInkTouchesAtTouchLocation:(CGPoint)location {
   NSIndexPath* indexPath =
       [self.collectionView indexPathForItemAtPoint:location];
   TabHistoryCell* cell = base::mac::ObjCCastStrict<TabHistoryCell>(
       [self.collectionView cellForItemAtIndexPath:indexPath]);
   if (!cell) {
     return NO;
   }
 
   // Increase the size of the ink view to cover the collection view from edge
   // to edge.
   CGRect inkViewFrame = [cell frame];
   inkViewFrame.origin.x = 0;
   inkViewFrame.size.width = CGRectGetWidth([self.collectionView bounds]);
   [[inkTouchController defaultInkView] setFrame:inkViewFrame];
   return YES;
 }
 
 @end