Track parent-child relations during profiling

chrome/browser/chrome_browser_main.cc

 // Copyright (c) 2012 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 1129 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()));
   }
 
+  // Default to basic profiling (no parent child support).
+  tracked_objects::ThreadData::Status status =
+        tracked_objects::ThreadData::PROFILING_ACTIVE;
   if (parsed_command_line().HasSwitch(switches::kEnableProfiling)) {
     // User wants to override default tracking status.
     std::string flag =
       parsed_command_line().GetSwitchValueASCII(switches::kEnableProfiling);
-    bool enabled = flag.compare("0") != 0;
-    tracked_objects::ThreadData::InitializeAndSetTrackingStatus(enabled);
+    if (flag.compare("0") != 0)
+      status = tracked_objects::ThreadData::DEACTIVATED;
+    else if (flag.compare("child") != 0)
+      status = tracked_objects::ThreadData::PROFILING_CHILDREN_ACTIVE;
   }
+  tracked_objects::ThreadData::InitializeAndSetTrackingStatus(status);
 
   // This forces the TabCloseableStateWatcher to be created and, on chromeos,
   // register for the notifications it needs to track the closeable state of
   // tabs.
   browser_process_->tab_closeable_state_watcher();
 
   local_state_ = InitializeLocalState(parsed_command_line(),
                                       is_first_run_);
 
   // These members must be initialized before returning from this function.
@@ skipping 769 matching lines @@
     if (base::win::GetVersion() <= base::win::VERSION_XP)
       uma_name += "_XP";
 
     uma_name += "_PreRead";
     uma_name += pre_read == "1" ? "Enabled" : "Disabled";
     AddPreReadHistogramTime(uma_name.c_str(), time);
   }
 #endif
 #endif
 }