Don't crash in StatisticsRecorder if VLOG level changes.

base/metrics/statistics_recorder.cc

Index: base/metrics/statistics_recorder.cc
diff --git a/base/metrics/statistics_recorder.cc b/base/metrics/statistics_recorder.cc
index 39ecc30a359986c3bb5567cef83f410a155f9f8a..cadfc9ffec42e0cd954a77a9feaf3822082f92ee 100644
--- a/base/metrics/statistics_recorder.cc
+++ b/base/metrics/statistics_recorder.cc
@@ -286,7 +286,8 @@ StatisticsRecorder::StatisticsRecorder() {
 
 // static
 void StatisticsRecorder::DumpHistogramsToVlog(void* instance) {
-  DCHECK(VLOG_IS_ON(1));
+  if (!VLOG_IS_ON(1))
+    return;

[Ilya Sherman, 2015/05/12 20:18:34]

I think we can just remove this check.  The function is only registered as a
callback when vlog is on at construction time, so in normal operation there's no
way to hit this path.

Alternately, you could remove the check on line 283.

 
   string output;
   StatisticsRecorder::WriteGraph(std::string(), &output);