Subject .mm files to the header sorting presubmit

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/profiles/avatar_label_button.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];
 }