[ObjC ARC] Converts ios/chrome/browser/ui/keyboard:unit_tests to ARC.Automatically generated ARCM…

ios/chrome/browser/ui/keyboard/hardware_keyboard_watcher_unittest.mm

 // Copyright 2015 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/keyboard/hardware_keyboard_watcher.h"
 
 #include "base/mac/scoped_nsobject.h"
 #include "base/test/histogram_tester.h"
 #include "testing/gtest/include/gtest/gtest.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
+
 namespace {
 
 void PostKeyboardWillChangeNotification(CGRect beginFrame, CGRect endFrame) {
   [[NSNotificationCenter defaultCenter]
       postNotificationName:UIKeyboardWillChangeFrameNotification
                     object:nil
                   userInfo:@{
                     UIKeyboardFrameBeginUserInfoKey :
                         [NSValue valueWithCGRect:beginFrame],
                     UIKeyboardFrameEndUserInfoKey :
@@ skipping 86 matching lines @@
       [[HardwareKeyboardWatcher alloc] initWithAccessoryView:mockView]);
 
   PostKeyboardWillChangeNotification(CGRectMake(0, -50, 100, 100),
                                      CGRectMake(0, 0, 100, 100));
 
   histogram_tester.ExpectUniqueSample("Omnibox.HardwareKeyboardModeEnabled",
                                       true, 1);
 }
 
 }  // namespace