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

ios/chrome/browser/ui/open_in_toolbar_unittest.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.
 
 #include "base/logging.h"
-#include "base/mac/scoped_nsobject.h"
 #import "ios/chrome/browser/ui/open_in_toolbar.h"
 #include "testing/platform_test.h"
 #import "third_party/ocmock/OCMock/OCMock.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 // A class that counts the number of times the |dummyMethod:| method is called.
 @interface DummyObserver : NSObject
 
 // The number of times |dummyMethod:| is invoked.
 @property(nonatomic, readonly) int dummyMethodCallCount;
 
 // The method whose invocation increases |dummyMethodCallCount| by one.
 - (void)dummyMethod:(id)parameter;
 
 @end
@@ skipping 18 matching lines @@
     for (UIView* subview in subviews) {
       if ([subview isKindOfClass:[UIButton class]]) {
         return (UIButton*)subview;
       }
     }
     return nil;
   }
 };
 
 TEST_F(OpenInToolbarTest, TestButtonActionAndSelector) {
-  base::scoped_nsobject<DummyObserver> dummyObserver(
-      [[DummyObserver alloc] init]);
-  base::scoped_nsobject<OpenInToolbar> openInToolbar([[OpenInToolbar alloc]
-      initWithTarget:dummyObserver
-              action:@selector(dummyMethod:)]);
+  DummyObserver* dummyObserver = [[DummyObserver alloc] init];
+  OpenInToolbar* openInToolbar =
+      [[OpenInToolbar alloc] initWithTarget:dummyObserver
+                                     action:@selector(dummyMethod:)];
   UIButton* button = GetOpenInButtonInToolBar(openInToolbar);
   ASSERT_TRUE(button);
   EXPECT_EQ([dummyObserver dummyMethodCallCount], 0);
   [button sendActionsForControlEvents:UIControlEventTouchUpInside];
   EXPECT_EQ([dummyObserver dummyMethodCallCount], 1);
 }
 
 }  // namespace