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

chrome/browser/ui/cocoa/constrained_window/constrained_window_custom_window_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 "base/mac/scoped_nsobject.h"
-#import "chrome/browser/ui/cocoa/cocoa_test_helper.h"
 #import "chrome/browser/ui/cocoa/constrained_window/constrained_window_custom_window.h"
+#import "chrome/browser/ui/cocoa/test/cocoa_test_helper.h"
 
 class ConstrainedWindowCustomWindowTest : public CocoaTest {
 };
 
 // Simply test creating and drawing the window.
 TEST_F(ConstrainedWindowCustomWindowTest, Basic) {
   base::scoped_nsobject<ConstrainedWindowCustomWindow> window(
       [[ConstrainedWindowCustomWindow alloc]
           initWithContentRect:NSMakeRect(0, 0, 10, 10)]);
   EXPECT_TRUE([window canBecomeKeyWindow]);
   EXPECT_FALSE([window canBecomeMainWindow]);
 
   [window makeKeyAndOrderFront:nil];
   [window display];
   [window close];
 }