Revert 107895 - Fully enable about:tracking by default

chrome/browser/chrome_browser_main.h

 // 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.
 
 #ifndef CHROME_BROWSER_CHROME_BROWSER_MAIN_H_
 #define CHROME_BROWSER_CHROME_BROWSER_MAIN_H_
 #pragma once
 
 #include "base/basictypes.h"
 #include "base/gtest_prod_util.h"
@@ skipping 100 matching lines @@
 
   const MainFunctionParams& parameters_;
   const CommandLine& parsed_command_line_;
   int result_code_;
 
   // Create ShutdownWatcherHelper object for watching jank during shutdown.
   // Please keep |shutdown_watcher| as the first object constructed, and hence
   // it is destroyed last.
   scoped_ptr<ShutdownWatcherHelper> shutdown_watcher_;
 
+#if defined(TRACK_ALL_TASK_OBJECTS)
   // Creating this object starts tracking the creation and deletion of Task
   // instance. This MUST be done before main_message_loop, so that it is
   // destroyed after the main_message_loop.
   tracked_objects::AutoTracking tracking_objects_;
+#endif
 
   // Statistical testing infrastructure for the entire browser. NULL until
   // SetupMetricsAndFieldTrials is called.
   scoped_ptr<base::FieldTrialList> field_trial_list_;
 
   // Members initialized after / released before main_message_loop_ ------------
 
   scoped_ptr<BrowserProcessImpl> browser_process_;
   scoped_refptr<HistogramSynchronizer> histogram_synchronizer_;
   scoped_ptr<ProcessSingleton> process_singleton_;
@@ skipping 26 matching lines @@
 // Records the time from our process' startup to the present time in
 // the UMA histogram |metric_name|.
 void RecordBrowserStartupTime();
 
 // Records a time value to an UMA histogram in the context of the
 // PreReadExperiment field-trial. This also reports to the appropriate
 // sub-histogram (_PreRead(Enabled|Disabled)).
 void RecordPreReadExperimentTime(const char* name, base::TimeDelta time);
 
 #endif  // CHROME_BROWSER_CHROME_BROWSER_MAIN_H_