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

base/message_loop.cc

 // Copyright (c) 2009 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 "base/message_loop.h"
 
 #include <algorithm>
 
 #include "base/compiler_specific.h"
 #include "base/lazy_instance.h"
@@ skipping 513 matching lines @@
 
 // static
 void MessageLoop::EnableHistogrammer(bool enable) {
   enable_histogrammer_ = enable;
 }
 
 void MessageLoop::StartHistogrammer() {
   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_);
   }
 }
 
 void MessageLoop::HistogramEvent(int event) {
   if (message_histogram_.get())
     message_histogram_->Add(event);
 }
 
@@ skipping 79 matching lines @@
                                            Watcher *delegate) {
   return pump_libevent()->WatchFileDescriptor(
       fd,
       persistent,
       static_cast<base::MessagePumpLibevent::Mode>(mode),
       controller,
       delegate);
 }
 
 #endif