Create c/b/ui/cocoa/test and move test files to there

chrome/browser/ui/cocoa/constrained_window/constrained_window_sheet_controller_unittest.mm

 // Copyright (c) 2012 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 "chrome/browser/ui/cocoa/constrained_window/constrained_window_sheet_controller.h"
 
 #include <stddef.h>
 
 #include "base/mac/sdk_forward_declarations.h"
 #include "base/macros.h"
-#import "chrome/browser/ui/cocoa/cocoa_test_helper.h"
 #import "chrome/browser/ui/cocoa/constrained_window/constrained_window_custom_sheet.h"
+#import "chrome/browser/ui/cocoa/test/cocoa_test_helper.h"
 #import "testing/gtest_mac.h"
 
 namespace {
 
 const int kSystemSheetReturnCode = 77;
 
 }  // namespace
 
 @interface ConstrainedWindowSystemSheetTest
     : NSObject <ConstrainedWindowSheet> {
@@ skipping 304 matching lines @@
   [system_sheet setAlert:alert];
 
   EXPECT_FALSE([[alert window] isVisible]);
   [controller_ showSheet:system_sheet forParentView:active_tab_view_];
   EXPECT_TRUE([[alert window] isVisible]);
 
   [controller_ closeSheet:system_sheet];
   EXPECT_FALSE([[alert window] isVisible]);
   EXPECT_EQ(kSystemSheetReturnCode, [system_sheet returnCode]);
 }