Migrate chrome/browser files to histogram_macros.h includes.

chrome/browser/diagnostics/diagnostics_metrics.cc

 // Copyright 2013 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/diagnostics/diagnostics_metrics.h"
 
 #include <string>
 
 #include "base/macros.h"
-#include "base/metrics/histogram.h"
+#include "base/metrics/histogram_macros.h"
 #include "chrome/browser/diagnostics/diagnostics_test.h"
 
 namespace diagnostics {
 
 namespace {
 
 // A struct to hold information about the tests.
 struct TestNameInfo {
   // Should only contain characters [A-Za-z0-9] (no spaces).
   const char* name;
@@ skipping 102 matching lines @@
   switch (id) {
     TEST_CASES(name);  // See above
     default:
       NOTREACHED() << "Unhandled UMA Metric type" << id;
   }
 }
 #undef TEST_CASE
 #undef TEST_CASES
 
 }  // namespace diagnostics