Migrate content/ files to histogram_macros.h includes.

content/renderer/media/webrtc/processed_local_audio_source.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/webrtc/processed_local_audio_source.h"
 
 #include "base/logging.h"
-#include "base/metrics/histogram.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/strings/stringprintf.h"
 #include "content/renderer/media/audio_device_factory.h"
 #include "content/renderer/media/media_stream_audio_processor_options.h"
 #include "content/renderer/media/media_stream_constraints_util.h"
 #include "content/renderer/media/webrtc/peer_connection_dependency_factory.h"
 #include "content/renderer/media/webrtc_audio_device_impl.h"
 #include "content/renderer/media/webrtc_logging.h"
 #include "content/renderer/render_frame_impl.h"
 #include "media/audio/sample_rates.h"
 #include "media/base/channel_layout.h"
@@ skipping 347 matching lines @@
 
   // If the buffer size is missing from the StreamDeviceInfo, provide 10ms as a
   // fall-back.
   //
   // TODO(miu): Identify where/why the buffer size might be missing, fix the
   // code, and then require it here. http://crbug.com/638081
   return (sample_rate / 100);
 }
 
 }  // namespace content