[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 177 matching lines @@
     [attributes setFrame:LayoutRectGetRect(cellLayout)];
     [attributes setZIndex:0];
   }
 
   return attributes;
 }
 
 @end
 
 @interface TabHistoryViewController ()<MDCInkTouchControllerDelegate> {
-  base::scoped_nsobject<MDCInkTouchController> _inkTouchController;
-  base::scoped_nsobject<NSArray> _partitionedEntries;
-  base::scoped_nsobject<NSArray> _sessionEntries;
+  MDCInkTouchController* _inkTouchController;
+  NSArray* _partitionedEntries;
+  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()) {
+  for (NSArray* sectionArray in _partitionedEntries) {
     NSUInteger sectionItemCount = [sectionArray count];
     for (NSUInteger i = 0; i < sectionItemCount; ++i) {
       CGFloat proposedHeight = optimalHeight + kCellHeight;
 
       if (proposedHeight > suggestedHeight) {
         CGFloat difference = proposedHeight - suggestedHeight;
         if (difference > kCellHeightLastRow) {
           return optimalHeight + kCellHeightLastRow;
         } else {
           return optimalHeight - kCellHeight + kCellHeightLastRow;
         }
       }
 
       optimalHeight = proposedHeight;
     }
 
     optimalHeight += FooterHeight();
   }
 
   // If this point is reached, it means the entire content fits and this last
   // section should not include the footer.
   optimalHeight -= FooterHeight();
 
   return optimalHeight;
 }
 
 - (instancetype)init {
-  base::scoped_nsobject<TabHistoryViewControllerLayout> layout(
-      [[TabHistoryViewControllerLayout alloc] init]);
+  TabHistoryViewControllerLayout* layout =
+      [[TabHistoryViewControllerLayout alloc] init];
 
   return [self initWithCollectionViewLayout:layout];
 }
 
 - (instancetype)initWithCollectionViewLayout:(UICollectionViewLayout*)layout {
   self = [super initWithCollectionViewLayout:layout];
   if (self) {
     UICollectionView* collectionView = [self collectionView];
     [collectionView setBackgroundColor:[UIColor whiteColor]];
 
     [collectionView registerClass:[TabHistoryCell class]
         forCellWithReuseIdentifier:cellIdentifier];
 
     [collectionView registerClass:[TabHistorySectionHeader class]
         forSupplementaryViewOfKind:UICollectionElementKindSectionHeader
                withReuseIdentifier:headerIdentifier];
 
     [collectionView registerClass:[TabHistorySectionFooter class]
         forSupplementaryViewOfKind:UICollectionElementKindSectionFooter
                withReuseIdentifier:footerIdentifier];
 
-    _inkTouchController.reset(
-        [[MDCInkTouchController alloc] initWithView:collectionView]);
+    _inkTouchController =
+        [[MDCInkTouchController alloc] initWithView:collectionView];
     [_inkTouchController setDelegate:self];
     [_inkTouchController addInkView];
   }
 
   return self;
 }
 
 #pragma mark UICollectionViewDelegate
 
 - (void)collectionView:(UICollectionView*)collectionView
@@ skipping 62 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 = 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 = 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