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

Semi-autogenerated ARCMigrate commit.
Notable issues:
 * Since one of the weak_nsobjects is exposed in a header and I change it to a __weak instead, converted two unit tests to ARC alongside this.
 * Fixed some assignments of newly created views to weak properties by introducing an intermediate local variable to retain the view until it's added as subview.

BUG=624363
TEST=None

Review-Url: https://codereview.chromium.org/2624963003
Cr-Commit-Position: refs/heads/master@{#443240}

ios/chrome/browser/ui/history/BUILD.gn

@@ -3,6 +3,7 @@
 # found in the LICENSE file.
 
 source_set("history") {
+  configs += [ "//build/config/compiler:enable_arc" ]
   sources = [
     "clear_browsing_bar.h",
     "clear_browsing_bar.mm",
@@ -93,12 +94,10 @@ source_set("unit_tests") {
   testonly = true
   sources = [
     "favicon_view_provider_unittest.mm",
-    "history_collection_view_controller_unittest.mm",
     "history_entries_status_item_unittest.mm",
     "history_entry_inserter_unittest.mm",
     "history_entry_item_unittest.mm",
     "history_search_view_controller_unittest.mm",
-    "history_service_facade_unittest.mm",
     "history_util_unittest.mm",
     "tab_history_popup_controller_unittest.mm",
   ]
@@ -133,10 +132,59 @@ source_set("unit_tests") {
     "//ui/gfx",
     "//url",
   ]
+
+  public_deps = [
+    ":unit_tests_arc",
+  ]
+  allow_circular_includes_from = [ ":unit_tests_arc" ]
+}
+
+source_set("unit_tests_arc") {
+  testonly = true
+  configs += [ "//build/config/compiler:enable_arc" ]
+
+  sources = [
+    "history_collection_view_controller_unittest.mm",
+    "history_service_facade_unittest.mm",
+  ]
+  deps = [
+    ":history",
+    ":resources_unit_tests",
+    "//base",
+    "//base/test:test_support",
+    "//components/favicon/core",
+    "//components/favicon_base",
+    "//components/history/core/browser",
+    "//components/keyed_service/core",
+    "//components/sessions",
+    "//components/strings",
+    "//ios/chrome/app/strings",
+    "//ios/chrome/browser",
+    "//ios/chrome/browser/browser_state:test_support",
+    "//ios/chrome/browser/history",
+    "//ios/chrome/browser/signin",
+    "//ios/chrome/browser/signin:test_support",
+    "//ios/chrome/browser/ui",
+    "//ios/chrome/browser/ui/collection_view",
+    "//ios/chrome/browser/ui/util",
+    "//ios/chrome/common",
+    "//ios/chrome/test:test_support",
+    "//ios/web",
+    "//ios/web:test_support",
+    "//skia",
+    "//testing/gtest",
+    "//third_party/ocmock",
+    "//ui/base",
+    "//ui/gfx",
+    "//url",
+  ]
 }
 
 bundle_data("resources_unit_tests") {
-  visibility = [ ":unit_tests" ]
+  visibility = [
+    ":unit_tests",
+    ":unit_tests_arc",
+  ]
   testonly = true
   sources = [
     "//ios/chrome/test/data/favicon/test_favicon.png",

ios/chrome/browser/ui/history/clear_browsing_bar.mm

@@ -5,7 +5,6 @@
 #import "ios/chrome/browser/ui/history/clear_browsing_bar.h"
 
 #include "base/logging.h"
-#include "base/mac/objc_property_releaser.h"
 #include "components/strings/grit/components_strings.h"
 #include "ios/chrome/browser/ui/rtl_geometry.h"
 #import "ios/chrome/browser/ui/uikit_ui_util.h"
@@ -13,6 +12,10 @@
 #import "ios/third_party/material_components_ios/src/components/Typography/src/MaterialTypography.h"
 #include "ui/base/l10n/l10n_util_mac.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 // Shadow opacity for the clear browsing bar.
 CGFloat kShadowOpacity = 0.2f;
@@ -22,9 +25,7 @@ CGFloat kHorizontalMargin = 8.0f;
 typedef NS_ENUM(BOOL, ButtonPlacement) { Leading, Trailing };
 }  // namespace
 
-@interface ClearBrowsingBar () {
-  base::mac::ObjCPropertyReleaser propertyReleaser_ClearBrowsingBar_;
-}
+@interface ClearBrowsingBar ()
 
 // Button that displays "Clear Browsing Data...".
 @property(nonatomic, strong) UIButton* clearBrowsingDataButton;
@@ -56,27 +57,26 @@ typedef NS_ENUM(BOOL, ButtonPlacement) { Leading, Trailing };
 - (instancetype)initWithFrame:(CGRect)frame {
   self = [super initWithFrame:frame];
   if (self) {
-    _clearBrowsingDataButton =
-        [[UIButton buttonWithType:UIButtonTypeCustom] retain];
+    _clearBrowsingDataButton = [UIButton buttonWithType:UIButtonTypeCustom];
     [_clearBrowsingDataButton
         setTitle:l10n_util::GetNSStringWithFixup(
                      IDS_HISTORY_OPEN_CLEAR_BROWSING_DATA_DIALOG)
         forState:UIControlStateNormal];
     [self styleButton:_clearBrowsingDataButton forPlacement:Leading];
 
-    _editButton = [[UIButton buttonWithType:UIButtonTypeCustom] retain];
+    _editButton = [UIButton buttonWithType:UIButtonTypeCustom];
     [_editButton
         setTitle:l10n_util::GetNSString(IDS_HISTORY_START_EDITING_BUTTON)
         forState:UIControlStateNormal];
     [self styleButton:_editButton forPlacement:Trailing];
 
-    _deleteButton = [[UIButton buttonWithType:UIButtonTypeCustom] retain];
+    _deleteButton = [UIButton buttonWithType:UIButtonTypeCustom];
     [_deleteButton setTitle:l10n_util::GetNSString(
                                 IDS_HISTORY_DELETE_SELECTED_ENTRIES_BUTTON)
                    forState:UIControlStateNormal];
     [self styleButton:_deleteButton forPlacement:Leading];
 
-    _cancelButton = [[UIButton buttonWithType:UIButtonTypeCustom] retain];
+    _cancelButton = [UIButton buttonWithType:UIButtonTypeCustom];
     [_cancelButton
         setTitle:l10n_util::GetNSString(IDS_HISTORY_CANCEL_EDITING_BUTTON)
         forState:UIControlStateNormal];
@@ -106,7 +106,6 @@ typedef NS_ENUM(BOOL, ButtonPlacement) { Leading, Trailing };
     [self setBackgroundColor:[UIColor whiteColor]];
     [[self layer] setShadowOpacity:kShadowOpacity];
     [self setEditing:NO];
-    propertyReleaser_ClearBrowsingBar_.Init(self, [ClearBrowsingBar class]);
   }
   return self;
 }

ios/chrome/browser/ui/history/favicon_view.h

@@ -12,9 +12,9 @@
 // Size for the favicon.
 @property(nonatomic) CGFloat size;
 // Image view for the favicon.
-@property(nonatomic, retain) UIImageView* faviconImage;
+@property(nonatomic, strong) UIImageView* faviconImage;
 // Label for fallback favicon placeholder.
-@property(nonatomic, retain) UILabel* faviconFallbackLabel;
+@property(nonatomic, strong) UILabel* faviconFallbackLabel;
 
 @end
 

ios/chrome/browser/ui/history/favicon_view.mm

@@ -4,9 +4,12 @@
 
 #import "ios/chrome/browser/ui/history/favicon_view.h"
 
-#include "base/mac/objc_property_releaser.h"
 #import "ios/chrome/browser/ui/uikit_ui_util.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 // Default corner radius for the favicon image view.
 const CGFloat kDefaultCornerRadius = 3;
@@ -14,7 +17,6 @@ const CGFloat kDefaultCornerRadius = 3;
 
 @interface FaviconView () {
   // Property releaser for FaviconView.
-  base::mac::ObjCPropertyReleaser _propertyReleaser_FaviconView;
 }
 // Size constraints for the favicon views.
 @property(nonatomic, copy) NSArray* faviconSizeConstraints;
@@ -30,7 +32,6 @@ const CGFloat kDefaultCornerRadius = 3;
 - (instancetype)initWithFrame:(CGRect)frame {
   self = [super initWithFrame:frame];
   if (self) {
-    _propertyReleaser_FaviconView.Init(self, [FaviconView class]);
     _faviconImage = [[UIImageView alloc] init];
     _faviconImage.clipsToBounds = YES;
     _faviconImage.layer.cornerRadius = kDefaultCornerRadius;
@@ -51,10 +52,10 @@ const CGFloat kDefaultCornerRadius = 3;
     AddSameSizeConstraint(_faviconImage, self);
     AddSameCenterConstraints(_faviconFallbackLabel, self);
     AddSameSizeConstraint(_faviconFallbackLabel, self);
-    _faviconSizeConstraints = [@[
+    _faviconSizeConstraints = @[
       [self.widthAnchor constraintEqualToConstant:0],
       [self.heightAnchor constraintEqualToConstant:0],
-    ] retain];
+    ];
     [NSLayoutConstraint activateConstraints:_faviconSizeConstraints];
   }
   return self;

ios/chrome/browser/ui/history/favicon_view_provider.h

@@ -38,7 +38,7 @@ class GURL;
 - (instancetype)init NS_UNAVAILABLE;
 
 // View that displays a favicon or fallback icon.
-@property(nonatomic, readonly) FaviconView* faviconView;
+@property(strong, nonatomic, readonly) FaviconView* faviconView;
 
 @end
 

ios/chrome/browser/ui/history/favicon_view_provider.mm

@@ -5,11 +5,8 @@
 #import "ios/chrome/browser/ui/history/favicon_view_provider.h"
 
 #include "base/i18n/case_conversion.h"
-#include "base/ios/weak_nsobject.h"
 #include "base/mac/bind_objc_block.h"
 #import "base/mac/foundation_util.h"
-#include "base/mac/objc_property_releaser.h"
-#include "base/mac/scoped_nsobject.h"
 #include "base/memory/ref_counted_memory.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/strings/utf_string_conversions.h"
@@ -24,30 +21,30 @@
 #include "skia/ext/skia_utils_ios.h"
 #include "url/gurl.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 @interface FaviconViewProvider () {
-  // Property releaser for FaviconViewProvider.
-  base::mac::ObjCPropertyReleaser _propertyReleaser_FaviconViewProvider;
   // Delegate for handling completion of favicon load.
-  base::WeakNSProtocol<id<FaviconViewProviderDelegate>> _delegate;
+  __weak id<FaviconViewProviderDelegate> _delegate;
   // Used to cancel tasks for the LargeIconService.
   base::CancelableTaskTracker _faviconTaskTracker;
-  // View that renders a favicon or a fallback image.
-  base::scoped_nsobject<FaviconView> _faviconView;
 }
 
 // Size to render the favicon.
 @property(nonatomic, assign) CGFloat faviconSize;
 // Favicon image for the favicon view.
-@property(nonatomic, retain) UIImage* favicon;
+@property(nonatomic, strong) UIImage* favicon;
 // Fallback text for the favicon view if there is no appropriately sized
 // favicon availabile.
 @property(nonatomic, copy) NSString* fallbackText;
 // Fallback background color for the favicon view if there is no appropriately
 // sized favicon available.
-@property(nonatomic, retain) UIColor* fallbackBackgroundColor;
+@property(nonatomic, strong) UIColor* fallbackBackgroundColor;
 // Fallback text color for the favicon view if there is no appropriately
 // sized favicon available.
-@property(nonatomic, retain) UIColor* fallbackTextColor;
+@property(nonatomic, strong) UIColor* fallbackTextColor;
 
 // Fetches favicon for |URL| from |faviconService|. Notifies delegate when
 // favicon is retrieved.
@@ -65,6 +62,7 @@
 @synthesize fallbackText = _fallbackText;
 @synthesize fallbackBackgroundColor = _fallbackBackgroundColor;
 @synthesize fallbackTextColor = _fallbackTextColor;
+@synthesize faviconView = _faviconView;
 
 - (instancetype)initWithURL:(const GURL&)URL
                 faviconSize:(CGFloat)faviconSize
@@ -73,12 +71,10 @@
                    delegate:(id<FaviconViewProviderDelegate>)delegate {
   self = [super init];
   if (self) {
-    _propertyReleaser_FaviconViewProvider.Init(self,
-                                               [FaviconViewProvider class]);
     _faviconSize = faviconSize;
-    _delegate.reset(delegate);
-    _fallbackBackgroundColor = [[UIColor grayColor] retain];
-    _fallbackTextColor = [[UIColor whiteColor] retain];
+    _delegate = delegate;
+    _fallbackBackgroundColor = [UIColor grayColor];
+    _fallbackTextColor = [UIColor whiteColor];
     [self fetchFaviconForURL:URL
                         size:faviconSize
                      minSize:minFaviconSize
@@ -98,11 +94,11 @@
                    service:(favicon::LargeIconService*)largeIconService {
   if (!largeIconService)
     return;
-  base::WeakNSObject<FaviconViewProvider> weakSelf(self);
+  __weak FaviconViewProvider* weakSelf = self;
   GURL blockURL(URL);
   void (^faviconBlock)(const favicon_base::LargeIconResult&) = ^(
       const favicon_base::LargeIconResult& result) {
-    base::scoped_nsobject<FaviconViewProvider> strongSelf([weakSelf retain]);
+    FaviconViewProvider* strongSelf = weakSelf;
     if (!strongSelf)
       return;
     if (result.bitmap.is_valid()) {
@@ -122,36 +118,35 @@
       [strongSelf setFallbackText:base::SysUTF16ToNSString(
                                       favicon::GetFallbackIconText(blockURL))];
     }
-    [strongSelf.get()->_delegate faviconViewProviderFaviconDidLoad:strongSelf];
+    [strongSelf->_delegate faviconViewProviderFaviconDidLoad:strongSelf];
   };
 
   // Always call LargeIconService in case the favicon was updated.
   CGFloat faviconSize = [UIScreen mainScreen].scale * size;
   CGFloat minFaviconSize = [UIScreen mainScreen].scale * minSize;
   largeIconService->GetLargeIconOrFallbackStyle(
-      URL, minFaviconSize, faviconSize, base::BindBlock(faviconBlock),
+      URL, minFaviconSize, faviconSize, base::BindBlockArc(faviconBlock),
       &_faviconTaskTracker);
 }
 
 - (FaviconView*)faviconView {
   if (!_faviconView) {
-    _faviconView.reset([[FaviconView alloc] initWithFrame:CGRectZero]);
+    _faviconView = [[FaviconView alloc] initWithFrame:CGRectZero];
   }
-  _faviconView.get().size = _faviconSize;
+  _faviconView.size = _faviconSize;
   // Update favicon view with current properties.
   if (self.favicon) {
-    _faviconView.get().faviconImage.image = self.favicon;
-    _faviconView.get().faviconImage.backgroundColor = [UIColor whiteColor];
-    _faviconView.get().faviconFallbackLabel.text = nil;
+    _faviconView.faviconImage.image = self.favicon;
+    _faviconView.faviconImage.backgroundColor = [UIColor whiteColor];
+    _faviconView.faviconFallbackLabel.text = nil;
   } else {
-    _faviconView.get().faviconImage.image = nil;
-    _faviconView.get().faviconImage.backgroundColor =
-        self.fallbackBackgroundColor;
-    _faviconView.get().faviconFallbackLabel.text = self.fallbackText;
-    _faviconView.get().faviconFallbackLabel.textColor = self.fallbackTextColor;
+    _faviconView.faviconImage.image = nil;
+    _faviconView.faviconImage.backgroundColor = self.fallbackBackgroundColor;
+    _faviconView.faviconFallbackLabel.text = self.fallbackText;
+    _faviconView.faviconFallbackLabel.textColor = self.fallbackTextColor;
 
     CGFloat fontSize = floorf(_faviconSize / 2);
-    _faviconView.get().faviconFallbackLabel.font =
+    _faviconView.faviconFallbackLabel.font =
         [[MDFRobotoFontLoader sharedInstance] regularFontOfSize:fontSize];
   }
   return _faviconView;

ios/chrome/browser/ui/history/history_collection_view_controller.mm

@@ -8,10 +8,7 @@
 
 #include <memory>
 
-#import "base/ios/weak_nsobject.h"
 #include "base/mac/foundation_util.h"
-#import "base/mac/objc_property_releaser.h"
-#include "base/mac/scoped_nsobject.h"
 #include "base/metrics/user_metrics.h"
 #include "base/metrics/user_metrics_action.h"
 #include "base/strings/sys_string_conversions.h"
@@ -40,6 +37,7 @@
 #include "ios/chrome/browser/ui/history/history_util.h"
 #import "ios/chrome/browser/ui/url_loader.h"
 #include "ios/chrome/grit/ios_strings.h"
+#import "ios/third_party/material_components_ios/src/components/ActivityIndicator/src/MDCActivityIndicator.h"
 #import "ios/third_party/material_components_ios/src/components/Collections/src/MaterialCollections.h"
 #import "ios/third_party/material_components_ios/src/components/Palettes/src/MaterialPalettes.h"
 #import "ios/web/public/referrer.h"
@@ -48,6 +46,10 @@
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/l10n/l10n_util_mac.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 typedef NS_ENUM(NSInteger, ItemType) {
   ItemTypeHistoryEntry = kItemTypeEnumZero,
@@ -66,30 +68,27 @@ const CGFloat kSeparatorInset = 10;
                                               HistoryEntryInserterDelegate,
                                               HistoryEntryItemDelegate,
                                               HistoryServiceFacadeDelegate> {
-  base::mac::ObjCPropertyReleaser
-      _propertyReleaser_HistoryCollectionViewController;
   // Facade for communicating with HistoryService and WebHistoryService.
   std::unique_ptr<HistoryServiceFacade> _historyServiceFacade;
   // The main browser state. Not owned by HistoryCollectionViewController.
   ios::ChromeBrowserState* _browserState;
   // Backing ivar for delegate property.
-  base::WeakNSProtocol<id<HistoryCollectionViewControllerDelegate>> _delegate;
+  __weak id<HistoryCollectionViewControllerDelegate> _delegate;
   // Backing ivar for URLLoader property.
-  base::WeakNSProtocol<id<UrlLoader>> _URLLoader;
+  __weak id<UrlLoader> _URLLoader;
 }
 
 // Object to manage insertion of history entries into the collection view model.
-@property(nonatomic, retain) HistoryEntryInserter* entryInserter;
+@property(nonatomic, strong) HistoryEntryInserter* entryInserter;
 // Delegate for the history collection view.
-@property(nonatomic, assign, readonly)
-    id<HistoryCollectionViewControllerDelegate>
-        delegate;
+@property(nonatomic, weak, readonly) id<HistoryCollectionViewControllerDelegate>
+    delegate;
 // UrlLoader for navigating to history entries.
-@property(nonatomic, assign, readonly) id<UrlLoader> URLLoader;
+@property(nonatomic, weak, readonly) id<UrlLoader> URLLoader;
 // The current query for visible history entries.
 @property(nonatomic, copy) NSString* currentQuery;
 // Coordinator for displaying context menus for history entries.
-@property(nonatomic, assign) ContextMenuCoordinator* contextMenuCoordinator;
+@property(nonatomic, strong) ContextMenuCoordinator* contextMenuCoordinator;
 // Type of displayed history entries. Entries can be synced or local, or there
 // may be no history entries.
 @property(nonatomic, assign) HistoryEntriesStatus entriesType;
@@ -151,12 +150,10 @@ const CGFloat kSeparatorInset = 10;
                                    delegate {
   self = [super initWithStyle:CollectionViewControllerStyleDefault];
   if (self) {
-    _propertyReleaser_HistoryCollectionViewController.Init(
-        self, [HistoryCollectionViewController class]);
     _historyServiceFacade.reset(new HistoryServiceFacade(browserState, self));
     _browserState = browserState;
-    _delegate.reset(delegate);
-    _URLLoader.reset(loader);
+    _delegate = delegate;
+    _URLLoader = loader;
     [self loadModel];
     // Add initial info section as header.
     [self.collectionViewModel
@@ -181,10 +178,10 @@ const CGFloat kSeparatorInset = 10;
   self.collectionView.keyboardDismissMode =
       UIScrollViewKeyboardDismissModeOnDrag;
 
-  base::scoped_nsobject<UILongPressGestureRecognizer> longPressRecognizer([
+  UILongPressGestureRecognizer* longPressRecognizer = [
       [UILongPressGestureRecognizer alloc]
       initWithTarget:self
-              action:@selector(displayContextMenuInvokedByGestureRecognizer:)]);
+              action:@selector(displayContextMenuInvokedByGestureRecognizer:)];
   [self.collectionView addGestureRecognizer:longPressRecognizer];
 }
 
@@ -357,19 +354,17 @@ const CGFloat kSeparatorInset = 10;
   // loading indicator removal will not be observed.
   [self updateEntriesStatusMessage];
 
-  __block base::scoped_nsobject<NSMutableArray> filterResults(
-      [[NSMutableArray array] retain]);
-  __block base::scoped_nsobject<NSString> searchQuery(
-      [base::SysUTF16ToNSString(result.query) copy]);
+  __block NSMutableArray* filterResults = [NSMutableArray array];
+  __block NSString* searchQuery = [base::SysUTF16ToNSString(result.query) copy];
   [self.collectionView performBatchUpdates:^{
     // There should always be at least a header section present.
     DCHECK([[self collectionViewModel] numberOfSections]);
     for (const history::HistoryEntry& entry : entries) {
       HistoryEntryItem* item =
-          [[[HistoryEntryItem alloc] initWithType:ItemTypeHistoryEntry
-                                     historyEntry:entry
-                                     browserState:_browserState
-                                         delegate:self] autorelease];
+          [[HistoryEntryItem alloc] initWithType:ItemTypeHistoryEntry
+                                    historyEntry:entry
+                                    browserState:_browserState
+                                        delegate:self];
       [self.entryInserter insertHistoryEntryItem:item];
       if ([self isSearching] || self.filterQueryResult) {
         [filterResults addObject:item];
@@ -573,16 +568,15 @@ const CGFloat kSeparatorInset = 10;
 - (void)updateEntriesStatusMessage {
   CollectionViewItem* entriesStatusItem = nil;
   if (!self.hasHistoryEntries) {
-    CollectionViewTextItem* noResultsItem = [[[CollectionViewTextItem alloc]
-        initWithType:ItemTypeEntriesStatus] autorelease];
+    CollectionViewTextItem* noResultsItem =
+        [[CollectionViewTextItem alloc] initWithType:ItemTypeEntriesStatus];
     noResultsItem.text =
         self.isSearching ? l10n_util::GetNSString(IDS_HISTORY_NO_SEARCH_RESULTS)
                          : l10n_util::GetNSString(IDS_HISTORY_NO_RESULTS);
     entriesStatusItem = noResultsItem;
   } else {
     HistoryEntriesStatusItem* historyEntriesStatusItem =
-        [[[HistoryEntriesStatusItem alloc] initWithType:ItemTypeEntriesStatus]
-            autorelease];
+        [[HistoryEntriesStatusItem alloc] initWithType:ItemTypeEntriesStatus];
     historyEntriesStatusItem.delegate = self;
     AuthenticationService* authService =
         AuthenticationServiceFactory::GetForBrowserState(_browserState);
@@ -691,8 +685,8 @@ const CGFloat kSeparatorInset = 10;
           fromSectionWithIdentifier:kSectionIdentifierEnumZero];
       [self.collectionView deleteItemsAtIndexPaths:@[ indexPath ]];
     }
-    CollectionViewItem* loadingIndicatorItem = [[[CollectionViewItem alloc]
-        initWithType:ItemTypeActivityIndicator] autorelease];
+    CollectionViewItem* loadingIndicatorItem =
+        [[CollectionViewItem alloc] initWithType:ItemTypeActivityIndicator];
     loadingIndicatorItem.cellClass = [ActivityIndicatorCell class];
     [self.collectionViewModel addItem:loadingIndicatorItem
               toSectionWithIdentifier:kEntriesStatusSectionIdentifier];
@@ -724,10 +718,10 @@ const CGFloat kSeparatorInset = 10;
   HistoryEntryItem* entry = base::mac::ObjCCastStrict<HistoryEntryItem>(
       [self.collectionViewModel itemAtIndexPath:touchedItemIndexPath]);
 
-  base::WeakNSObject<HistoryCollectionViewController> weakSelf(self);
+  __weak HistoryCollectionViewController* weakSelf = self;
   web::ContextMenuParams params;
   params.location = touchLocation;
-  params.view.reset([self.collectionView retain]);
+  params.view.reset(self.collectionView);
   NSString* menuTitle =
       base::SysUTF16ToNSString(url_formatter::FormatUrl(entry.URL));
   params.menu_title.reset([menuTitle copy]);

ios/chrome/browser/ui/history/history_collection_view_controller_unittest.mm

@@ -6,7 +6,6 @@
 
 #include <memory>
 
-#import "base/mac/scoped_nsobject.h"
 #include "base/strings/string16.h"
 #import "base/test/ios/wait_util.h"
 #include "base/time/time.h"
@@ -61,31 +60,27 @@ class HistoryCollectionViewControllerTest : public BlockCleanupTest {
         AuthenticationServiceFactory::GetInstance(),
         AuthenticationServiceFake::CreateAuthenticationService);
     mock_browser_state_ = builder.Build();
-    mock_delegate_.reset([[OCMockObject
-        niceMockForProtocol:@protocol(HistoryCollectionViewControllerDelegate)]
-        retain]);
-    mock_url_loader_.reset(
-        [[OCMockObject niceMockForProtocol:@protocol(UrlLoader)] retain]);
-    history_collection_view_controller_.reset(
+    mock_delegate_ = [OCMockObject
+        niceMockForProtocol:@protocol(HistoryCollectionViewControllerDelegate)];
+    mock_url_loader_ = [OCMockObject niceMockForProtocol:@protocol(UrlLoader)];
+    history_collection_view_controller_ =
         [[HistoryCollectionViewController alloc]
             initWithLoader:mock_url_loader_
               browserState:mock_browser_state_.get()
-                  delegate:mock_delegate_]);
+                  delegate:mock_delegate_];
   }
 
   void TearDown() override {
-    history_collection_view_controller_.reset();
+    history_collection_view_controller_ = nil;
     BlockCleanupTest::TearDown();
   }
 
  protected:
   web::TestWebThreadBundle thread_bundle_;
-  base::scoped_nsprotocol<id<UrlLoader>> mock_url_loader_;
+  id<UrlLoader> mock_url_loader_;
   std::unique_ptr<TestChromeBrowserState> mock_browser_state_;
-  base::scoped_nsprotocol<id<HistoryCollectionViewControllerDelegate>>
-      mock_delegate_;
-  base::scoped_nsobject<HistoryCollectionViewController>
-      history_collection_view_controller_;
+  id<HistoryCollectionViewControllerDelegate> mock_delegate_;
+  HistoryCollectionViewController* history_collection_view_controller_;
   bool privacy_settings_opened_;
   DISALLOW_COPY_AND_ASSIGN(HistoryCollectionViewControllerTest);
 };

ios/chrome/browser/ui/history/history_entries_status_item.h

@@ -38,7 +38,7 @@ class GURL;
 // YES if message for other forms of browsing data should be shown.
 @property(nonatomic, assign) BOOL showsOtherBrowsingDataNotice;
 // Delegate for HistoryEntriesStatusItem. Is notified when a link is pressed.
-@property(nonatomic, assign) id<HistoryEntriesStatusItemDelegate> delegate;
+@property(nonatomic, weak) id<HistoryEntriesStatusItemDelegate> delegate;
 @end
 
 // Cell for displaying status for history entry. Provides information on whether

ios/chrome/browser/ui/history/history_entries_status_item.mm

@@ -4,9 +4,7 @@
 
 #import "ios/chrome/browser/ui/history/history_entries_status_item.h"
 
-#include "base/ios/weak_nsobject.h"
 #include "base/mac/foundation_util.h"
-#import "base/mac/objc_property_releaser.h"
 #include "components/strings/grit/components_strings.h"
 #include "ios/chrome/browser/chrome_url_constants.h"
 #import "ios/chrome/browser/ui/collection_view/cells/collection_view_footer_item.h"
@@ -18,6 +16,10 @@
 #include "ui/base/l10n/l10n_util_mac.h"
 #include "url/gurl.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 // Delegate for HistoryEntriesStatusCell.
 @protocol HistoryEntriesStatusCellDelegate<NSObject>
 // Notifies the delegate that |URL| should be opened.
@@ -25,33 +27,25 @@
                didRequestOpenURL:(const GURL&)URL;
 @end
 
-@interface HistoryEntriesStatusCell () {
-  // Property releaser for HistoryEntriesStatusItem.
-  base::mac::ObjCPropertyReleaser _propertyReleaser_HistoryEntriesStatusCell;
-  // Delegate for the HistoryEntriesStatusCell. Is notified when a link is
-  // tapped.
-  base::WeakNSProtocol<id<HistoryEntriesStatusCellDelegate>> _delegate;
-}
+@interface HistoryEntriesStatusCell ()
 // Redeclare as readwrite.
-@property(nonatomic, retain, readwrite)
+@property(nonatomic, strong, readwrite)
     LabelLinkController* labelLinkController;
 // Delegate for the HistoryEntriesStatusCell. Is notified when a link is
 // tapped.
-@property(nonatomic, assign) id<HistoryEntriesStatusCellDelegate> delegate;
+// Delegate for the HistoryEntriesStatusCell. Is notified when a link is
+// tapped.
+@property(nonatomic, weak) id<HistoryEntriesStatusCellDelegate> delegate;
 // Sets links on the cell label.
 - (void)setLinksForSyncURL:(const GURL&)syncURL
            browsingDataURL:(const GURL&)browsingDataURL;
 @end
 
-@interface HistoryEntriesStatusItem ()<HistoryEntriesStatusCellDelegate> {
-  // Delegate for the HistoryEntriesStatusItem. Is notified when a link is
-  // tapped.
-  base::WeakNSProtocol<id<HistoryEntriesStatusItemDelegate>> _delegate;
-}
+@interface HistoryEntriesStatusItem ()<HistoryEntriesStatusCellDelegate>
 @end
 
 @implementation HistoryEntriesStatusItem
-
+@synthesize delegate = _delegate;
 @synthesize entriesStatus = _entriesStatus;
 @synthesize hidden = _hidden;
 @synthesize showsOtherBrowsingDataNotice = _showsOtherBrowsingDataNotice;
@@ -112,14 +106,6 @@
            browsingDataURL:otherBrowsingDataURL];
 }
 
-- (void)setDelegate:(id<HistoryEntriesStatusItemDelegate>)delegate {
-  _delegate.reset(delegate);
-}
-
-- (id<HistoryEntriesStatusItemDelegate>)delegate {
-  return _delegate;
-}
-
 - (void)historyEntriesStatusCell:(HistoryEntriesStatusCell*)cell
                didRequestOpenURL:(const GURL&)URL {
   [self.delegate historyEntriesStatusItem:self didRequestOpenURL:URL];
@@ -146,27 +132,18 @@
 @end
 
 @implementation HistoryEntriesStatusCell
-
+@synthesize delegate = _delegate;
 @synthesize labelLinkController = _labelLinkController;
 
-- (instancetype)initWithFrame:(CGRect)frame {
-  self = [super initWithFrame:frame];
-  if (self) {
-    _propertyReleaser_HistoryEntriesStatusCell.Init(
-        self, [HistoryEntriesStatusCell class]);
-  }
-  return self;
-}
-
 - (void)setLinksForSyncURL:(const GURL&)syncURL
            browsingDataURL:(const GURL&)browsingDataURL {
-  base::WeakNSObject<HistoryEntriesStatusCell> weakSelf(self);
-  self.labelLinkController = [[[LabelLinkController alloc]
+  __weak HistoryEntriesStatusCell* weakSelf = self;
+  self.labelLinkController = [[LabelLinkController alloc]
       initWithLabel:self.textLabel
              action:^(const GURL& URL) {
                [[weakSelf delegate] historyEntriesStatusCell:weakSelf
                                            didRequestOpenURL:URL];
-             }] autorelease];
+             }];
   [self.labelLinkController setLinkColor:[[MDCPalette cr_bluePalette] tint500]];
 
   // Remove link delimiters from text and get ranges for links. Both links
@@ -196,14 +173,6 @@
   }
 }
 
-- (void)setDelegate:(id<HistoryEntriesStatusCellDelegate>)delegate {
-  _delegate.reset(delegate);
-}
-
-- (id<HistoryEntriesStatusCellDelegate>)delegate {
-  return _delegate;
-}
-
 - (void)prepareForReuse {
   [super prepareForReuse];
   self.labelLinkController = nil;

ios/chrome/browser/ui/history/history_entry_inserter.h

@@ -36,7 +36,7 @@ class Time;
 
 // Delegate for the HistoryEntryInserter. Receives callbacks upon item and
 // section insertion and removal.
-@property(nonatomic, assign) id<HistoryEntryInserterDelegate> delegate;
+@property(nonatomic, weak) id<HistoryEntryInserterDelegate> delegate;
 
 // Designated initializer for HistoryEntryInserter. collectionViewModel is the
 // model into which entries are inserted. Sections for history entries are

ios/chrome/browser/ui/history/history_entry_inserter.mm

@@ -4,9 +4,7 @@
 
 #import "ios/chrome/browser/ui/history/history_entry_inserter.h"
 
-#import "base/ios/weak_nsobject.h"
 #include "base/mac/foundation_util.h"
-#include "base/mac/scoped_nsobject.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/time/time.h"
 #import "ios/chrome/browser/ui/collection_view/cells/collection_view_text_item.h"
@@ -15,42 +13,38 @@
 #include "ios/chrome/browser/ui/history/history_util.h"
 #include "url/gurl.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 @interface HistoryEntryInserter () {
-  // Delegate for the HistoryEntryInserter.
-  base::WeakNSProtocol<id<HistoryEntryInserterDelegate>> _delegate;
   // CollectionViewModel in which to insert history entries.
-  base::scoped_nsobject<CollectionViewModel> _collectionViewModel;
+  CollectionViewModel* _collectionViewModel;
   // The index of the first section to contain history entries.
   NSInteger _firstSectionIndex;
   // Number of assigned section identifiers.
   NSInteger _sectionIdentifierCount;
   // Sorted set of dates that have history entries.
-  base::scoped_nsobject<NSMutableOrderedSet> _dates;
+  NSMutableOrderedSet* _dates;
   // Mapping from dates to section identifiers.
-  base::scoped_nsobject<NSMutableDictionary> _sectionIdentifiers;
+  NSMutableDictionary* _sectionIdentifiers;
 }
 
 @end
 
 @implementation HistoryEntryInserter
+@synthesize delegate = _delegate;
 
 - (instancetype)initWithModel:(CollectionViewModel*)collectionViewModel {
   if ((self = [super init])) {
-    _collectionViewModel.reset([collectionViewModel retain]);
+    _collectionViewModel = collectionViewModel;
     _firstSectionIndex = [collectionViewModel numberOfSections];
-    _dates.reset([[NSMutableOrderedSet alloc] init]);
-    _sectionIdentifiers.reset([[NSMutableDictionary dictionary] retain]);
+    _dates = [[NSMutableOrderedSet alloc] init];
+    _sectionIdentifiers = [NSMutableDictionary dictionary];
   }
   return self;
 }
 
-- (id<HistoryEntryInserterDelegate>)delegate {
-  return _delegate;
-}
-
-- (void)setDelegate:(id<HistoryEntryInserterDelegate>)delegate {
-  _delegate.reset(delegate);
-}
 
 - (void)insertHistoryEntryItem:(HistoryEntryItem*)item {
   NSInteger sectionIdentifier =
@@ -126,8 +120,8 @@
                            usingComparator:comparator];
   [_dates insertObject:date atIndex:index];
   NSInteger insertionIndex = _firstSectionIndex + index;
-  CollectionViewTextItem* header = [[[CollectionViewTextItem alloc]
-      initWithType:kItemTypeEnumZero] autorelease];
+  CollectionViewTextItem* header =
+      [[CollectionViewTextItem alloc] initWithType:kItemTypeEnumZero];
   header.text =
       base::SysUTF16ToNSString(history::GetRelativeDateLocalized(timestamp));
   [_collectionViewModel insertSectionWithIdentifier:sectionIdentifier

ios/chrome/browser/ui/history/history_entry_item.h

@@ -75,13 +75,13 @@ class GURL;
 @interface HistoryEntryCell : MDCCollectionViewCell
 
 // View for displaying the favicon for the history entry.
-@property(nonatomic, retain) UIView* faviconViewContainer;
+@property(nonatomic, strong) UIView* faviconViewContainer;
 // Text label for history entry title.
-@property(nonatomic, readonly, retain) UILabel* textLabel;
+@property(nonatomic, readonly, strong) UILabel* textLabel;
 // Text label for history entry URL.
-@property(nonatomic, readonly, retain) UILabel* detailTextLabel;
+@property(nonatomic, readonly, strong) UILabel* detailTextLabel;
 // Text label for history entry timestamp.
-@property(nonatomic, readonly, retain) UILabel* timeLabel;
+@property(nonatomic, readonly, strong) UILabel* timeLabel;
 
 @end
 

ios/chrome/browser/ui/history/history_entry_item.mm

@@ -5,9 +5,7 @@
 #import "ios/chrome/browser/ui/history/history_entry_item.h"
 
 #include "base/i18n/time_formatting.h"
-#include "base/ios/weak_nsobject.h"
 #import "base/mac/foundation_util.h"
-#import "base/mac/objc_property_releaser.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "components/history/core/browser/url_row.h"
@@ -24,6 +22,10 @@
 #import "ios/third_party/material_roboto_font_loader_ios/src/src/MaterialRobotoFontLoader.h"
 #include "ui/base/l10n/l10n_util.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 // Size at which the favicon will be displayed.
 const CGFloat kFaviconSize = 24.0;
@@ -59,14 +61,12 @@ NSString* FormattedTitle(const base::string16& title, const GURL& url) {
 #pragma mark - HistoryEntryItem
 
 @interface HistoryEntryItem ()<FaviconViewProviderDelegate> {
-  // Property releaser for HistoryEntryItem.
-  base::mac::ObjCPropertyReleaser _propertyReleaser_HistoryEntryItem;
   // Delegate for HistoryEntryItem.
-  base::WeakNSProtocol<id<HistoryEntryItemDelegate>> _delegate;
+  __weak id<HistoryEntryItemDelegate> _delegate;
 }
 
 // FaviconViewProvider to fetch the favicon and format the favicon view.
-@property(nonatomic, retain) FaviconViewProvider* faviconViewProvider;
+@property(nonatomic, strong) FaviconViewProvider* faviconViewProvider;
 
 // Custom accessibility actions for the history entry view.
 - (NSArray*)accessibilityActions;
@@ -96,7 +96,6 @@ NSString* FormattedTitle(const base::string16& title, const GURL& url) {
                     delegate:(id<HistoryEntryItemDelegate>)delegate {
   self = [super initWithType:type];
   if (self) {
-    _propertyReleaser_HistoryEntryItem.Init(self, [HistoryEntryItem class]);
     self.cellClass = [HistoryEntryCell class];
     favicon::LargeIconService* largeIconService =
         IOSChromeLargeIconServiceFactory::GetForBrowserState(browserState);
@@ -112,7 +111,7 @@ NSString* FormattedTitle(const base::string16& title, const GURL& url) {
         [base::SysUTF16ToNSString(base::TimeFormatTimeOfDay(entry.time)) copy];
     _URL = GURL(entry.url);
     _timestamp = entry.time;
-    _delegate.reset(delegate);
+    _delegate = delegate;
   }
   return self;
 }
@@ -143,28 +142,28 @@ NSString* FormattedTitle(const base::string16& title, const GURL& url) {
 
 - (NSArray*)accessibilityActions {
   UIAccessibilityCustomAction* deleteAction =
-      [[[UIAccessibilityCustomAction alloc]
+      [[UIAccessibilityCustomAction alloc]
           initWithName:l10n_util::GetNSString(
                            IDS_HISTORY_ENTRY_ACCESSIBILITY_DELETE)
                 target:self
-              selector:@selector(deleteHistoryEntry)] autorelease];
+              selector:@selector(deleteHistoryEntry)];
   UIAccessibilityCustomAction* openInNewTabAction =
-      [[[UIAccessibilityCustomAction alloc]
+      [[UIAccessibilityCustomAction alloc]
           initWithName:l10n_util::GetNSString(
                            IDS_IOS_CONTENT_CONTEXT_OPENLINKNEWTAB)
                 target:self
-              selector:@selector(openInNewTab)] autorelease];
+              selector:@selector(openInNewTab)];
   UIAccessibilityCustomAction* openInNewIncognitoTabAction =
-      [[[UIAccessibilityCustomAction alloc]
+      [[UIAccessibilityCustomAction alloc]
           initWithName:l10n_util::GetNSString(
                            IDS_IOS_CONTENT_CONTEXT_OPENLINKNEWINCOGNITOTAB)
                 target:self
-              selector:@selector(openInNewIncognitoTab)] autorelease];
+              selector:@selector(openInNewIncognitoTab)];
   UIAccessibilityCustomAction* copyURLAction =
-      [[[UIAccessibilityCustomAction alloc]
+      [[UIAccessibilityCustomAction alloc]
           initWithName:l10n_util::GetNSString(IDS_IOS_CONTENT_CONTEXT_COPY)
                 target:self
-              selector:@selector(copyURL)] autorelease];
+              selector:@selector(copyURL)];
   return @[
     deleteAction, openInNewTabAction, openInNewIncognitoTabAction, copyURLAction
   ];
@@ -220,15 +219,12 @@ NSString* FormattedTitle(const base::string16& title, const GURL& url) {
 
 #pragma mark - HistoryEntryCell
 
-@interface HistoryEntryCell () {
-  // Property releaser for HistoryEntryCell.
-  base::mac::ObjCPropertyReleaser _propertyReleaser_HistoryEntryCell;
-}
+@interface HistoryEntryCell ()
 
-// Redeclare as readwrite to allow property releaser to handle these properties.
-@property(nonatomic, readwrite, retain) UILabel* textLabel;
-@property(nonatomic, readwrite, retain) UILabel* detailTextLabel;
-@property(nonatomic, readwrite, retain) UILabel* timeLabel;
+// Redeclare as readwrite.
+@property(nonatomic, readwrite, strong) UILabel* textLabel;
+@property(nonatomic, readwrite, strong) UILabel* detailTextLabel;
+@property(nonatomic, readwrite, strong) UILabel* timeLabel;
 @end
 
 @implementation HistoryEntryCell
@@ -241,7 +237,6 @@ NSString* FormattedTitle(const base::string16& title, const GURL& url) {
 - (id)initWithFrame:(CGRect)frame {
   self = [super initWithFrame:frame];
   if (self) {
-    _propertyReleaser_HistoryEntryCell.Init(self, [HistoryEntryCell class]);
 
     _faviconViewContainer = [[UIView alloc] initWithFrame:CGRectZero];
 

ios/chrome/browser/ui/history/history_search_view.mm

@@ -4,12 +4,15 @@
 
 #import "ios/chrome/browser/ui/history/history_search_view.h"
 
-#include "base/mac/objc_property_releaser.h"
 #include "components/strings/grit/components_strings.h"
 #include "ios/chrome/browser/ui/uikit_ui_util.h"
 #import "ios/third_party/material_components_ios/src/components/Typography/src/MaterialTypography.h"
 #include "ui/base/l10n/l10n_util_mac.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 // Shadow opacity for the search view.
 CGFloat kShadowOpacity = 0.2f;
@@ -17,9 +20,7 @@ CGFloat kShadowOpacity = 0.2f;
 CGFloat kHorizontalMargin = 16.0f;
 }  // namespace
 
-@interface HistorySearchView () {
-  base::mac::ObjCPropertyReleaser propertyReleaser_HistorySearchView_;
-}
+@interface HistorySearchView ()
 
 // Stack view for laying out the text field and cancel button.
 @property(nonatomic, strong) UIStackView* stackView;
@@ -58,7 +59,7 @@ CGFloat kHorizontalMargin = 16.0f;
     _textField.clearButtonMode = UITextFieldViewModeAlways;
     _textField.placeholder = l10n_util::GetNSString(IDS_HISTORY_SEARCH_BUTTON);
 
-    _cancelButton = [[UIButton buttonWithType:UIButtonTypeCustom] retain];
+    _cancelButton = [UIButton buttonWithType:UIButtonTypeCustom];
     [_cancelButton setImage:[UIImage imageNamed:@"collapse"]
                    forState:UIControlStateNormal];
     [_cancelButton setImage:[UIImage imageNamed:@"collapse_pressed"]
@@ -81,9 +82,9 @@ CGFloat kHorizontalMargin = 16.0f;
     _stackView.layoutMarginsRelativeArrangement = YES;
 
     CGFloat topAnchorConstant = IsCompact() ? StatusBarHeight() : 0;
-    _topAnchorConstraint = [[_stackView.topAnchor
-        constraintEqualToAnchor:self.topAnchor
-                       constant:topAnchorConstant] retain];
+    _topAnchorConstraint =
+        [_stackView.topAnchor constraintEqualToAnchor:self.topAnchor
+                                             constant:topAnchorConstant];
     [NSLayoutConstraint activateConstraints:@[
       _topAnchorConstraint,
       [_stackView.bottomAnchor constraintEqualToAnchor:self.bottomAnchor],
@@ -94,8 +95,6 @@ CGFloat kHorizontalMargin = 16.0f;
           constraintEqualToAnchor:self.trailingAnchor
                          constant:-kHorizontalMargin],
     ]];
-
-    propertyReleaser_HistorySearchView_.Init(self, [HistorySearchView class]);
   }
   return self;
 }

ios/chrome/browser/ui/history/history_search_view_controller.mm

@@ -4,15 +4,15 @@
 
 #import "ios/chrome/browser/ui/history/history_search_view_controller.h"
 
-#include "base/ios/weak_nsobject.h"
-#include "base/mac/scoped_nsobject.h"
 #import "ios/chrome/browser/ui/history/history_search_view.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 @interface HistorySearchViewController ()<UITextFieldDelegate> {
-  // Delegate for forwarding interactions with the search view.
-  base::WeakNSProtocol<id<HistorySearchViewControllerDelegate>> _delegate;
   // View displayed by the HistorySearchViewController
-  base::scoped_nsobject<HistorySearchView> _searchView;
+  HistorySearchView* _searchView;
 }
 
 // Action for the cancel button.
@@ -21,11 +21,11 @@
 @end
 
 @implementation HistorySearchViewController
-
+@synthesize delegate = _delegate;
 @synthesize enabled = _enabled;
 
 - (void)loadView {
-  _searchView.reset([[HistorySearchView alloc] init]);
+  _searchView = [[HistorySearchView alloc] init];
   [_searchView setSearchBarDelegate:self];
   [_searchView setCancelTarget:self action:@selector(cancelButtonClicked:)];
   self.view = _searchView;
@@ -36,14 +36,6 @@
   [_searchView becomeFirstResponder];
 }
 
-- (void)setDelegate:(id<HistorySearchViewControllerDelegate>)delegate {
-  _delegate.reset(delegate);
-}
-
-- (id<HistorySearchViewControllerDelegate>)delegate {
-  return _delegate;
-}
-
 - (void)setEnabled:(BOOL)enabled {
   _enabled = enabled;
   [_searchView setEnabled:enabled];

ios/chrome/browser/ui/history/history_service_facade.h

@@ -8,7 +8,6 @@
 #include <memory>
 #include <string>
 
-#include "base/ios/weak_nsobject.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/scoped_observer.h"
@@ -165,7 +164,7 @@ class HistoryServiceFacade : public history::HistoryServiceObserver {
   ios::ChromeBrowserState* browser_state_;  // weak
 
   // Delegate for HistoryServiceFacade. Serves as client for HistoryService.
-  base::WeakNSProtocol<id<HistoryServiceFacadeDelegate>> delegate_;
+  __weak id<HistoryServiceFacadeDelegate> delegate_;
 
   base::WeakPtrFactory<HistoryServiceFacade> weak_factory_;
 

ios/chrome/browser/ui/history/history_service_facade.mm

@@ -37,6 +37,10 @@
 #include "ios/chrome/browser/ui/history/history_service_facade_delegate.h"
 #include "ios/chrome/browser/ui/history/history_util.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 // The amount of time to wait for a response from the WebHistoryService.
 static const int kWebHistoryTimeoutSeconds = 3;
 
@@ -128,7 +132,7 @@ HistoryServiceFacade::HistoryServiceFacade(
 HistoryServiceFacade::~HistoryServiceFacade() {
   query_task_tracker_.TryCancelAll();
   web_history_request_.reset();
-  delegate_.reset();
+  delegate_ = nil;
 }
 
 void HistoryServiceFacade::QueryHistory(const base::string16& search_text,

ios/chrome/browser/ui/history/history_service_facade_unittest.mm

@@ -6,7 +6,6 @@
 
 #include <memory>
 
-#import "base/mac/scoped_nsobject.h"
 #include "base/run_loop.h"
 #include "base/strings/string16.h"
 #include "components/history/core/browser/history_service.h"
@@ -106,7 +105,7 @@ class HistoryServiceFacadeTest : public PlatformTest,
     bool success = browser_state_->CreateHistoryService(true);
     EXPECT_TRUE(success);
 
-    mock_delegate_.reset([[MockHistoryServiceFacadeDelegate alloc] init]);
+    mock_delegate_ = [[MockHistoryServiceFacadeDelegate alloc] init];
     history_service_facade_.reset(
         new HistoryServiceFacade(browser_state_.get(), mock_delegate_));
   }
@@ -176,7 +175,7 @@ class HistoryServiceFacadeTest : public PlatformTest,
  protected:
   web::TestWebThreadBundle thread_bundle_;
   std::unique_ptr<TestChromeBrowserState> browser_state_;
-  base::scoped_nsobject<MockHistoryServiceFacadeDelegate> mock_delegate_;
+  MockHistoryServiceFacadeDelegate* mock_delegate_;
   std::unique_ptr<HistoryServiceFacade> history_service_facade_;
   GURL visited_url_;
   base::Time visited_time_;

ios/chrome/browser/ui/history/history_util.mm

@@ -14,6 +14,10 @@
 #include "ui/base/l10n/time_format.h"
 #include "url/gurl.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace history {
 
 base::string16 GetRelativeDateLocalized(const base::Time& visit_time) {

ios/chrome/browser/ui/history/tab_history_cell.h

@@ -11,14 +11,14 @@
 
 // Table cell used in TabHistoryViewController.
 @interface TabHistoryCell : UICollectionViewCell
-@property(nonatomic, retain) CRWSessionEntry* entry;
-@property(nonatomic, readonly) UILabel* titleLabel;
+@property(strong, nonatomic) CRWSessionEntry* entry;
+@property(weak, nonatomic, readonly) UILabel* titleLabel;
 @end
 
 // Header for a section of TabHistoryCells.
 @interface TabHistorySectionHeader : UICollectionReusableView
-@property(nonatomic, readonly) UIImageView* iconView;
-@property(nonatomic, readonly) UIView* lineView;
+@property(weak, nonatomic, readonly) UIImageView* iconView;
+@property(weak, nonatomic, readonly) UIView* lineView;
 @end
 
 // Footer for a section of TabHistoryCells.

ios/chrome/browser/ui/history/tab_history_cell.mm

@@ -4,7 +4,6 @@
 
 #import "ios/chrome/browser/ui/history/tab_history_cell.h"
 
-#include "base/mac/scoped_nsobject.h"
 #include "base/strings/sys_string_conversions.h"
 #include "ios/chrome/browser/ui/ui_util.h"
 #import "ios/chrome/browser/ui/uikit_ui_util.h"
@@ -12,6 +11,10 @@
 #import "ios/web/navigation/crw_session_entry.h"
 #include "ios/web/public/navigation_item.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 // Header horizontal layout inset.
 const CGFloat kHeaderHorizontalInset = 16;
@@ -40,8 +43,8 @@ NS_INLINE CGFloat HeaderLineRadius() {
 }
 
 @implementation TabHistoryCell {
-  base::scoped_nsobject<CRWSessionEntry> _entry;
-  base::scoped_nsobject<UILabel> _titleLabel;
+  CRWSessionEntry* _entry;
+  UILabel* _titleLabel;
 }
 
 - (instancetype)initWithFrame:(CGRect)frame {
@@ -61,7 +64,7 @@ NS_INLINE CGFloat HeaderLineRadius() {
 }
 
 - (void)commonInitialization {
-  _titleLabel.reset([[UILabel alloc] initWithFrame:CGRectZero]);
+  _titleLabel = [[UILabel alloc] initWithFrame:CGRectZero];
   [_titleLabel setTextColor:UIColorFromRGB(kTitleTextRGB)];
   [_titleLabel
       setFont:[[MDFRobotoFontLoader sharedInstance] regularFontOfSize:16]];
@@ -77,11 +80,11 @@ NS_INLINE CGFloat HeaderLineRadius() {
 }
 
 - (CRWSessionEntry*)entry {
-  return [[_entry retain] autorelease];
+  return _entry;
 }
 
 - (void)setEntry:(CRWSessionEntry*)entry {
-  _entry.reset([entry retain]);
+  _entry = entry;
 
   NSString* title = nil;
   web::NavigationItem* navigationItem = [_entry navigationItem];
@@ -99,12 +102,12 @@ NS_INLINE CGFloat HeaderLineRadius() {
 }
 
 - (UILabel*)titleLabel {
-  return [[_titleLabel retain] autorelease];
+  return _titleLabel;
 }
 
 - (void)prepareForReuse {
   [super prepareForReuse];
-  _entry.reset(nil);
+  _entry = nil;
   [_titleLabel setText:nil];
   [self setAccessibilityLabel:nil];
 }
@@ -112,28 +115,28 @@ NS_INLINE CGFloat HeaderLineRadius() {
 @end
 
 @implementation TabHistorySectionHeader {
-  base::scoped_nsobject<UIImageView> _iconView;
-  base::scoped_nsobject<UIView> _lineView;
+  UIImageView* _iconView;
+  UIView* _lineView;
 }
 
 - (UIImageView*)iconView {
-  return [[_iconView retain] autorelease];
+  return _iconView;
 }
 
 - (UIView*)lineView {
-  return [[_lineView retain] autorelease];
+  return _lineView;
 }
 
 - (instancetype)initWithFrame:(CGRect)frame {
   self = [super initWithFrame:frame];
   if (self) {
     CGRect iconFrame = CGRectMake(0, 0, kSiteIconViewWidth, kSiteIconViewWidth);
-    _iconView.reset([[UIImageView alloc] initWithFrame:iconFrame]);
+    _iconView = [[UIImageView alloc] initWithFrame:iconFrame];
     [self addSubview:_iconView];
 
     UIColor* lineColor = UIColorFromRGB(kHeaderLineRGB);
 
-    _lineView.reset([[UIView alloc] initWithFrame:CGRectZero]);
+    _lineView = [[UIView alloc] initWithFrame:CGRectZero];
     [[_lineView layer] setCornerRadius:HeaderLineRadius()];
     [_lineView setBackgroundColor:lineColor];
     [self addSubview:_lineView];

ios/chrome/browser/ui/history/tab_history_popup_controller.mm

@@ -8,7 +8,6 @@
 
 #include "base/logging.h"
 #include "base/mac/bundle_locations.h"
-#include "base/mac/objc_property_releaser.h"
 #include "base/strings/sys_string_conversions.h"
 #import "ios/chrome/browser/ui/history/tab_history_view_controller.h"
 #import "ios/chrome/browser/ui/popup_menu/popup_menu_view.h"
@@ -21,6 +20,10 @@
 #import "ui/gfx/ios/NSString+CrStringDrawing.h"
 #include "ui/gfx/ios/uikit_util.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 static const CGFloat kTabHistoryMinWidth = 250.0;
 static const CGFloat kTabHistoryMaxWidthLandscapePhone = 350.0;
@@ -44,17 +47,15 @@ static const CGFloat kHeightPercentage = 0.85;
 
   // Container view of the history entries table.
   UIView* tabHistoryTableViewContainer_;
-
-  base::mac::ObjCPropertyReleaser propertyReleaser_TabHistoryPopupController_;
 }
 
 // Determines the width for the popup depending on the device, orientation, and
 // CRWSessionEntrys to display.
 - (CGFloat)calculatePopupWidth:(NSArray*)entries;
 
-@property(nonatomic, retain)
+@property(nonatomic, strong)
     TabHistoryViewController* tabHistoryTableViewController;
-@property(nonatomic, retain) UIView* tabHistoryTableViewContainer;
+@property(nonatomic, strong) UIView* tabHistoryTableViewContainer;
 
 @end
 
@@ -69,9 +70,6 @@ static const CGFloat kHeightPercentage = 0.85;
   DCHECK(parent);
   self = [super initWithParentView:parent];
   if (self) {
-    propertyReleaser_TabHistoryPopupController_.Init(
-        self, [TabHistoryPopupController class]);
-
     tabHistoryTableViewController_ = [[TabHistoryViewController alloc] init];
     [tabHistoryTableViewController_ setSessionEntries:entries];
 
@@ -168,7 +166,6 @@ static const CGFloat kHeightPercentage = 0.85;
 
 - (void)dealloc {
   [tabHistoryTableViewContainer_ removeFromSuperview];
-  [super dealloc];
 }
 
 @end

ios/chrome/browser/ui/history/tab_history_view_controller.h

@@ -12,7 +12,7 @@
 
 // TODO(crbug.com/546355): Convert this class to use an array of
 //    NavigationEntries.
-@property(nonatomic, retain) NSArray* sessionEntries;
+@property(nonatomic, strong) NSArray* sessionEntries;
 
 // Returns the optimal height needed to display the session entries.
 // The height returned is usually less than the |suggestedHeight| unless

ios/chrome/browser/ui/history/tab_history_view_controller.mm

@@ -4,11 +4,8 @@
 
 #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"
@@ -20,6 +17,10 @@
 #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
@@ -217,16 +218,16 @@ layoutAttributesForSupplementaryViewOfKind:(NSString*)kind
 @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
@@ -235,7 +236,7 @@ layoutAttributesForSupplementaryViewOfKind:(NSString*)kind
   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;
@@ -263,8 +264,8 @@ layoutAttributesForSupplementaryViewOfKind:(NSString*)kind
 }
 
 - (instancetype)init {
-  base::scoped_nsobject<TabHistoryViewControllerLayout> layout(
-      [[TabHistoryViewControllerLayout alloc] init]);
+  TabHistoryViewControllerLayout* layout =
+      [[TabHistoryViewControllerLayout alloc] init];
 
   return [self initWithCollectionViewLayout:layout];
 }
@@ -286,8 +287,8 @@ layoutAttributesForSupplementaryViewOfKind:(NSString*)kind
         forSupplementaryViewOfKind:UICollectionElementKindSectionFooter
                withReuseIdentifier:footerIdentifier];
 
-    _inkTouchController.reset(
-        [[MDCInkTouchController alloc] initWithView:collectionView]);
+    _inkTouchController =
+        [[MDCInkTouchController alloc] initWithView:collectionView];
     [_inkTouchController setDelegate:self];
     [_inkTouchController addInkView];
   }
@@ -370,7 +371,7 @@ layoutAttributesForSupplementaryViewOfKind:(NSString*)kind
 }
 
 - (void)setSessionEntries:(NSArray*)sessionEntries {
-  _sessionEntries.reset([sessionEntries retain]);
+  _sessionEntries = sessionEntries;
 
   std::string previousHost;
 
@@ -406,7 +407,7 @@ layoutAttributesForSupplementaryViewOfKind:(NSString*)kind
   if (![partitionedEntries count])
     partitionedEntries = nil;
 
-  _partitionedEntries.reset([partitionedEntries retain]);
+  _partitionedEntries = partitionedEntries;
 }
 
 #pragma mark MDCInkTouchControllerDelegate