Set process phases in the StackSamplingProfiler.

chrome/browser/chrome_browser_main.cc

Index: chrome/browser/chrome_browser_main.cc
diff --git a/chrome/browser/chrome_browser_main.cc b/chrome/browser/chrome_browser_main.cc
index 0e7089aaed6f3771a6922e0e0cd1a007afd97f56..a265f08238fa656d5bc04d17aa28ba0cf9d1ddae 100644
--- a/chrome/browser/chrome_browser_main.cc
+++ b/chrome/browser/chrome_browser_main.cc
@@ -27,6 +27,7 @@
 #include "base/metrics/histogram_macros.h"
 #include "base/path_service.h"
 #include "base/profiler/scoped_tracker.h"
+#include "base/profiler/stack_sampling_profiler.h"
 #include "base/run_loop.h"
 #include "base/strings/string16.h"
 #include "base/strings/string_number_conversions.h"
@@ -2053,6 +2054,11 @@ void ChromeBrowserMainParts::PostMainMessageLoopRun() {
 #endif  // defined(OS_ANDROID)
 }
 
+void ChromeBrowserMainParts::PreShutdown() {
+  base::StackSamplingProfiler::SetProcessMilestone(
+      metrics::CallStackProfileMetricsProvider::SHUTDOWN_START);
+}
+
 void ChromeBrowserMainParts::PostDestroyThreads() {
 #if defined(OS_ANDROID)
   // On Android, there is no quit/exit. So the browser's main message loop will