Migrate chrome/browser files to histogram_macros.h includes.

chrome/browser/metrics/chrome_browser_main_extra_parts_metrics_mac.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.
 
 #include "chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.h"
 
 #include "base/mac/sdk_forward_declarations.h"
-#include "base/metrics/histogram.h"
+#include "base/metrics/histogram_macros.h"
 
 namespace {
 
 // The possible values of the setting "Screens Have Separate Spaces".
 enum ScreenSpacesConfiguration {
   SCREENS_CANNOT_HAVE_SEPARATE_SPACES = 0,
   SCREENS_HAVE_SEPARATE_SPACES = 1,
   SCREENS_HAVE_SHARED_SPACES = 2,
   SCREEN_SPACES_CONFIGURATION_COUNT = 3
 };
 
 }  // namespace
 
 void ChromeBrowserMainExtraPartsMetrics::RecordMacMetrics() {
   ScreenSpacesConfiguration separate_spaces =
       SCREENS_CANNOT_HAVE_SEPARATE_SPACES;
 
   if ([NSScreen respondsToSelector:@selector(screensHaveSeparateSpaces)]) {
     BOOL screens_have_separate_spaces = [NSScreen screensHaveSeparateSpaces];
     separate_spaces = screens_have_separate_spaces
                           ? SCREENS_HAVE_SEPARATE_SPACES
                           : SCREENS_HAVE_SHARED_SPACES;
   }
   UMA_HISTOGRAM_ENUMERATION("OSX.Settings.ScreensHaveSeparateSpaces",
                             separate_spaces,
                             SCREEN_SPACES_CONFIGURATION_COUNT);
 }