[content] favor DCHECK_CURRENTLY_ON for better logs

content/browser/histogram_message_filter.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/browser/histogram_message_filter.h"
 
 #include "base/command_line.h"
 #include "base/metrics/histogram.h"
 #include "base/metrics/statistics_recorder.h"
 #include "content/browser/histogram_controller.h"
@@ skipping 23 matching lines @@
 void HistogramMessageFilter::OnChildHistogramData(
     int sequence_number,
     const std::vector<std::string>& pickled_histograms) {
   HistogramController::GetInstance()->OnHistogramDataCollected(
       sequence_number, pickled_histograms);
 }
 
 void HistogramMessageFilter::OnGetBrowserHistogram(
     const std::string& name,
     std::string* histogram_json) {
-  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
+  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
   // Security: Only allow access to browser histograms when running in the
   // context of a test.
   bool using_stats_collection_controller =
       base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kStatsCollectionController);
   if (!using_stats_collection_controller) {
     LOG(ERROR) << "Attempt at reading browser histogram without specifying "
                << "--" << switches::kStatsCollectionController << " switch.";
     return;
   }
   base::HistogramBase* histogram =
       base::StatisticsRecorder::FindHistogram(name);
   if (!histogram) {
     *histogram_json = "{}";
   } else {
     histogram->WriteJSON(histogram_json);
   }
 }
 
 }  // namespace content