[Mac] Remove some dead avatar menu code

chrome/browser/ui/cocoa/profiles/avatar_label_button_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.
-
-#import "chrome/browser/ui/cocoa/profiles/avatar_label_button.h"
-
-#import <Cocoa/Cocoa.h>
-
-#include "base/mac/scoped_nsobject.h"
-#import "chrome/browser/ui/cocoa/cocoa_test_helper.h"
-#include "testing/gtest/include/gtest/gtest.h"
-
-class AvatarLabelButtonTest : public CocoaTest {
- public:
-  AvatarLabelButtonTest() {
-    NSRect content_frame = [[test_window() contentView] frame];
-    button_.reset([[AvatarLabelButton alloc] initWithFrame:content_frame]);
-    [[test_window() contentView] addSubview:button_];
-  }
-
- protected:
-  base::scoped_nsobject<AvatarLabelButton> button_;
-};
-
-TEST_VIEW(AvatarLabelButtonTest, button_)
-
-TEST_F(AvatarLabelButtonTest, TestHighlight) {
-  EXPECT_FALSE([[button_ cell] isHighlighted]);
-  [button_ display];
-  [[button_ cell] setHighlighted:YES];
-  [button_ display];
-}