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

ios/chrome/browser/browsing_data/browsing_data_removal_controller_unittest.mm

Index: ios/chrome/browser/browsing_data/browsing_data_removal_controller_unittest.mm
diff --git a/ios/chrome/browser/browsing_data/browsing_data_removal_controller_unittest.mm b/ios/chrome/browser/browsing_data/browsing_data_removal_controller_unittest.mm
index ea36c2bf3c3ec6e036a395279e6e4a6b1ac58f54..a96c084f00a01fe0152faea54a36831a1b5886fc 100644
--- a/ios/chrome/browser/browsing_data/browsing_data_removal_controller_unittest.mm
+++ b/ios/chrome/browser/browsing_data/browsing_data_removal_controller_unittest.mm
@@ -6,7 +6,6 @@
 
 #include <memory>
 
-#import "base/mac/scoped_nsobject.h"
 #import "base/test/ios/wait_util.h"
 #include "ios/chrome/browser/browser_state/test_chrome_browser_state.h"
 #include "ios/web/public/test/web_test.h"
@@ -14,6 +13,10 @@
 #import "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
+
 typedef web::WebTest BrowsingDataRemovalControllerTest;
 
 // Tests that |removeIOSSpecificIncognitoBrowsingDataFromBrowserState:| can
@@ -22,8 +25,8 @@
   __block BOOL block_was_called = NO;
   id mock_delegate = [OCMockObject
       mockForProtocol:@protocol(BrowsingDataRemovalControllerDelegate)];
-  base::scoped_nsobject<BrowsingDataRemovalController> removal_controller(
-      [[BrowsingDataRemovalController alloc] initWithDelegate:mock_delegate]);
+  BrowsingDataRemovalController* removal_controller =
+      [[BrowsingDataRemovalController alloc] initWithDelegate:mock_delegate];
 
   TestChromeBrowserState::Builder builder;
   std::unique_ptr<TestChromeBrowserState> browser_state = builder.Build();