Move assorted function in application_lifetime to where they are used.

chrome/browser/browser_shutdown.cc

Index: chrome/browser/browser_shutdown.cc
diff --git a/chrome/browser/browser_shutdown.cc b/chrome/browser/browser_shutdown.cc
index aa7486c24e5ce6d29234c06e19b4d5880705bb84..c7ebc6ce5a1656a6b852f5e43c67948fdda6ca8e 100644
--- a/chrome/browser/browser_shutdown.cc
+++ b/chrome/browser/browser_shutdown.cc
@@ -19,6 +19,7 @@
 #include "base/strings/stringprintf.h"
 #include "base/threading/thread.h"
 #include "base/time/time.h"
+#include "base/trace_event/trace_event.h"
 #include "chrome/browser/about_flags.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/lifetime/application_lifetime.h"
@@ -30,6 +31,7 @@
 #include "chrome/common/pref_names.h"
 #include "chrome/common/switch_utils.h"
 #include "components/metrics/metrics_service.h"
+#include "components/tracing/tracing_switches.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/render_process_host.h"
 
@@ -112,7 +114,7 @@ void OnShutdownStarting(ShutdownType type) {
 #if !defined(OS_CHROMEOS)
   // Start the shutdown tracing. Note that On ChromeOS this has already been
   // called in AttemptUserExit().
-  chrome::StartShutdownTracing();
+  browser_shutdown::StartShutdownTracing();

[sky, 2015/10/07 17:12:32]

Isn't this code in the browser_shutdown namespace? Do you really need
browser_shutdown:: here?

[Lei Zhang, 2015/10/08 07:01:58]

Done.

 #endif
 
   g_shutdown_type = type;
@@ -346,4 +348,17 @@ bool IsTryingToQuit() {
   return g_trying_to_quit;
 }
 
+void StartShutdownTracing() {
+  const base::CommandLine& command_line =
+      *base::CommandLine::ForCurrentProcess();
+  if (command_line.HasSwitch(switches::kTraceShutdown)) {
+    base::trace_event::TraceConfig trace_config(
+        command_line.GetSwitchValueASCII(switches::kTraceShutdown), "");
+    base::trace_event::TraceLog::GetInstance()->SetEnabled(
+        trace_config,
+        base::trace_event::TraceLog::RECORDING_MODE);
+  }
+  TRACE_EVENT0("shutdown", "StartShutdownTracing");
+}
+
 }  // namespace browser_shutdown