Migrate content/ files to histogram_macros.h includes.

content/renderer/media/rtc_data_channel_handler.cc

 // Copyright (c) 2012 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 "content/renderer/media/rtc_data_channel_handler.h"
 
 #include <limits>
 #include <string>
 #include <utility>
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
-#include "base/metrics/histogram.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/thread_task_runner_handle.h"
 
 namespace content {
 
 namespace {
 
 enum DataChannelCounters {
   CHANNEL_CREATED,
   CHANNEL_OPENED,
@@ skipping 332 matching lines @@
                                 num_bytes,
                                 1, kMaxBucketSize, kNumBuckets);
   } else {
     UMA_HISTOGRAM_CUSTOM_COUNTS("WebRTC.UnreliableDataChannelMessageSize",
                                 num_bytes,
                                 1, kMaxBucketSize, kNumBuckets);
   }
 }
 
 }  // namespace content