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

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

 // Copyright 2016 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/history_collection_view_controller.h"
 
 #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"
 #include "ios/chrome/browser/browser_state/test_chrome_browser_state.h"
 #include "ios/chrome/browser/signin/authentication_service_factory.h"
 #include "ios/chrome/browser/signin/authentication_service_fake.h"
 #import "ios/chrome/browser/ui/history/history_entry.h"
 #import "ios/chrome/browser/ui/history/history_service_facade.h"
 #import "ios/chrome/browser/ui/history/history_service_facade_delegate.h"
 #import "ios/chrome/browser/ui/url_loader.h"
@@ skipping 34 matching lines @@
   ~HistoryCollectionViewControllerTest() override {}
 
   void SetUp() override {
     BlockCleanupTest::SetUp();
     DCHECK_CURRENTLY_ON(web::WebThread::UI);
     TestChromeBrowserState::Builder builder;
     builder.AddTestingFactory(
         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);
 };
 
 // Tests that hasHistoryEntries property returns YES after entries have been
 // received.
 TEST_F(HistoryCollectionViewControllerTest, HasHistoryEntries) {
   GURL url_1("http://test1");
   HistoryServiceFacade::QueryResult query_result =
       QueryResultWithVisits({{url_1, base::Time::Now()}});
@@ skipping 83 matching lines @@
   [collection_view
       selectItemAtIndexPath:[NSIndexPath indexPathForItem:0 inSection:2]
                    animated:NO
              scrollPosition:UICollectionViewScrollPositionNone];
   [history_collection_view_controller_ deleteSelectedItemsFromHistory];
 
   // Expect only the header section to remain.
   EXPECT_EQ(1, [collection_view numberOfSections]);
   EXPECT_EQ(1, [collection_view numberOfItemsInSection:0]);
 }