Track thread activities in order to diagnose hangs.

chrome/browser/chrome_browser_field_trials_desktop.cc

Index: chrome/browser/chrome_browser_field_trials_desktop.cc
diff --git a/chrome/browser/chrome_browser_field_trials_desktop.cc b/chrome/browser/chrome_browser_field_trials_desktop.cc
index d5761d4764d8bf1206947e1b248cf2f323ce71d4..1cff3e3f98233f913846805956d822e1517f4924 100644
--- a/chrome/browser/chrome_browser_field_trials_desktop.cc
+++ b/chrome/browser/chrome_browser_field_trials_desktop.cc
@@ -7,6 +7,7 @@
 #include <string>
 
 #include "base/command_line.h"
+#include "base/debug/activity_tracker.h"
 #include "base/metrics/field_trial.h"
 #include "chrome/browser/prerender/prerender_field_trial.h"
 #include "chrome/browser/tracing/background_tracing_field_trial.h"
@@ -52,6 +53,7 @@ void SetupStunProbeTrial() {
 void SetupDesktopFieldTrials(const base::CommandLine& parsed_command_line) {
   prerender::ConfigurePrerender(parsed_command_line);
   SetupLightSpeedTrials();
+  base::debug::SetupGlobalActivityTrackerFieldTrial();
   tracing::SetupBackgroundTracingFieldTrial();
   SetupStunProbeTrial();
 }