Creating a framework for suppressing pollution of the profiler data

base/profiler/scoped_profile.cc

 // Copyright (c) 2011 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/profiler/scoped_profile.h"
 
 #include "base/location.h"
 #include "base/tracked_objects.h"
 
 
 namespace tracked_objects {
 
 
 ScopedProfile::ScopedProfile(const Location& location)
-    : birth_(ThreadData::TallyABirthIfActive(location)),
-      start_of_run_(ThreadData::NowForStartOfRun(birth_)) {
+    : birth_(ThreadData::TallyABirthIfActive(location)) {
+  stopwatch_.Start(ThreadData::NowForStartOfRun(birth_));
 }
 
 ScopedProfile::~ScopedProfile() {
   StopClockAndTally();
 }
 
 void ScopedProfile::StopClockAndTally() {
+  stopwatch_.Stop(ThreadData::NowForEndOfRun());

[jar (doing other things), 2014/08/27 15:25:18]

Why do you need to stop the stopwatch if it is never tallied?

... i.e., why not move this t oafter line 27?

[vadimt, 2014/08/27 19:14:20]

Because Start and Stop should be strictly paired.
Start was called unconditionally. This means that Stop should be called
unconditionally.

+
   if (!birth_)
     return;
-  ThreadData::TallyRunInAScopedRegionIfTracking(birth_, start_of_run_,
-                                                ThreadData::NowForEndOfRun());
+  ThreadData::TallyRunInAScopedRegionIfTracking(birth_, stopwatch_);
   birth_ = NULL;
 }
 
 }  // namespace tracked_objects