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

chrome/browser/ui/cocoa/draggable_button_unittest.mm

 // Copyright (c) 2011 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/mac/scoped_nsobject.h"
-#import "chrome/browser/ui/cocoa/cocoa_test_helper.h"
 #import "chrome/browser/ui/cocoa/draggable_button.h"
+#import "chrome/browser/ui/cocoa/test/cocoa_test_helper.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/platform_test.h"
 #import "ui/events/test/cocoa_test_event_utils.h"
 
 @interface TestableDraggableButton : DraggableButton {
   NSUInteger dragCount_;
   BOOL wasTriggered_;
 }
 - (void)trigger:(id)sender;
 - (BOOL)wasTriggered;
@@ skipping 115 matching lines @@
   EXPECT_FALSE([[button cell] isHighlighted]);
   EXPECT_EQ(1U, [button dragCount]);
 
   // We should be able to initiate another drag immediately after the first one.
   [NSApp postEvent:upEvent atStart:YES];
   [NSApp postEvent:moveEvent atStart:YES];
   [button mouseDown:downEvent];
   EXPECT_EQ(2U, [button dragCount]);
   EXPECT_FALSE([[button cell] isHighlighted]);
 }