Use factory to create histograms, and refcounts to track lifetimes...

base/message_loop.cc

Index: base/message_loop.cc
===================================================================
--- base/message_loop.cc	(revision 33932)
+++ base/message_loop.cc	(working copy)
@@ -531,11 +531,12 @@
   if (enable_histogrammer_ && !message_histogram_.get()
       && StatisticsRecorder::WasStarted()) {
     DCHECK(!thread_name_.empty());
-    message_histogram_.reset(
-        new LinearHistogram(("MsgLoop:" + thread_name_).c_str(),
+    message_histogram_ =
+        LinearHistogram::LinearHistogramFactoryGet(
+                            ("MsgLoop:" + thread_name_),
                             kLeastNonZeroMessageId,
                             kMaxMessageId,
-                            kNumberOfDistinctMessagesDisplayed));
+                            kNumberOfDistinctMessagesDisplayed);
     message_histogram_->SetFlags(message_histogram_->kHexRangePrintingFlag);
     message_histogram_->SetRangeDescriptions(event_descriptions_);
   }