Fully enable about:tracking by default

chrome/browser/chrome_browser_main.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 "chrome/browser/chrome_browser_main.h"
 
 #include <algorithm>
 #include <string>
 #include <vector>
 
@@ skipping 1199 matching lines @@
       parsed_command_line().HasSwitch(switches::kImportFromFile)) {
     // We use different BrowserProcess when importing so no GoogleURLTracker is
     // instantiated (as it makes a net::URLRequest and we don't have an IO
     // thread, see bug #1292702).
     browser_process_.reset(new FirstRunBrowserProcess(parsed_command_line()));
     is_first_run = false;
   } else {
     browser_process_.reset(new BrowserProcessImpl(parsed_command_line()));
   }
 
+  if (parsed_command_line().HasSwitch(switches::kEnableTracking)) {
+    std::string flag =
+      parsed_command_line().GetSwitchValueASCII(switches::kEnableTracking);
+    if (flag.compare("0") == 0)
+       tracked_objects::ThreadData::InitializeAndSetTrackingStatus(false);
+  }
+
   // This forces the TabCloseableStateWatcher to be created and, on chromeos,
   // register for the notifications it needs to track the closeable state of
   // tabs.
   g_browser_process->tab_closeable_state_watcher();
 
   PrefService* local_state = InitializeLocalState(parsed_command_line(),
                                                   is_first_run);
 
 #if defined(USE_LINUX_BREAKPAD)
   // Needs to be called after we have chrome::DIR_USER_DATA and
@@ skipping 884 matching lines @@
   if (env->GetVar(chrome::kPreReadEnvironmentVariable, &pre_read) &&
       (pre_read == "0" || pre_read == "1")) {
     std::string uma_name(name);
     uma_name += "_PreRead";
     uma_name += pre_read == "1" ? "Enabled" : "Disabled";
     AddPreReadHistogramTime(uma_name.c_str(), time);
   }
 #endif
 #endif
 }