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

ios/chrome/browser/ui/settings/time_range_selector_collection_view_controller_unittest.mm

Index: ios/chrome/browser/ui/settings/time_range_selector_collection_view_controller_unittest.mm
diff --git a/ios/chrome/browser/ui/settings/time_range_selector_collection_view_controller_unittest.mm b/ios/chrome/browser/ui/settings/time_range_selector_collection_view_controller_unittest.mm
index d7a5b28188c790e14133c5289a1ce37652d78525..e0326ec0a58e07bdc8910c1a9e89f9203698125e 100644
--- a/ios/chrome/browser/ui/settings/time_range_selector_collection_view_controller_unittest.mm
+++ b/ios/chrome/browser/ui/settings/time_range_selector_collection_view_controller_unittest.mm
@@ -17,6 +17,10 @@
 #include "third_party/ocmock/OCMock/OCMock.h"
 #import "third_party/ocmock/gtest_support.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 @interface TimeRangeSelectorCollectionViewController (ExposedForTesting)
 - (void)updatePrefValue:(int)prefValue;
 @end
@@ -31,19 +35,18 @@ class TimeRangeSelectorCollectionViewControllerTest
   void SetUp() override {
     CollectionViewControllerTest::SetUp();
     pref_service_ = CreateLocalState();
-    delegate_.reset([[OCMockObject
+    delegate_ = [OCMockObject
         mockForProtocol:@protocol(
-                            TimeRangeSelectorCollectionViewControllerDelegate)]
-        retain]);
+                            TimeRangeSelectorCollectionViewControllerDelegate)];
     CreateController();
   }
 
-  CollectionViewController* NewController() override NS_RETURNS_RETAINED {
-    time_range_selector_controller_.reset(
+  CollectionViewController* InstantiateController() override {
+    time_range_selector_controller_ =
         [[TimeRangeSelectorCollectionViewController alloc]
             initWithPrefs:pref_service_.get()
-                 delegate:delegate_.get()]);
-    return [time_range_selector_controller_ retain];
+                 delegate:delegate_];
+    return time_range_selector_controller_;
   }
 
   std::unique_ptr<PrefService> CreateLocalState() {
@@ -63,9 +66,8 @@ class TimeRangeSelectorCollectionViewControllerTest
 
   base::MessageLoopForUI message_loop_;
   std::unique_ptr<PrefService> pref_service_;
-  base::scoped_nsobject<id> delegate_;
-  base::scoped_nsobject<TimeRangeSelectorCollectionViewController>
-      time_range_selector_controller_;
+  id delegate_;
+  TimeRangeSelectorCollectionViewController* time_range_selector_controller_;
 };
 
 TEST_F(TimeRangeSelectorCollectionViewControllerTest, TestModel) {
@@ -114,12 +116,12 @@ TEST_F(TimeRangeSelectorCollectionViewControllerTest, TestUpdateCheckedState) {
 TEST_F(TimeRangeSelectorCollectionViewControllerTest, TestUpdatePrefValue) {
   CheckController();
   UICollectionView* collectionView =
-      time_range_selector_controller_.get().collectionView;
+      time_range_selector_controller_.collectionView;
   for (NSInteger checkedItem = 0; checkedItem < kNumberOfItems; ++checkedItem) {
     NSIndexPath* indexPath =
         [NSIndexPath indexPathForItem:checkedItem inSection:0];
-    [[delegate_.get() expect]
-        timeRangeSelectorViewController:time_range_selector_controller_.get()
+    [[delegate_ expect]
+        timeRangeSelectorViewController:time_range_selector_controller_
                     didSelectTimePeriod:static_cast<browsing_data::TimePeriod>(
                                             checkedItem)];
     [time_range_selector_controller_ collectionView:collectionView