Set process phases in the StackSamplingProfiler.

content/public/browser/browser_main_parts.h

 // 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.
 
 #ifndef CONTENT_PUBLIC_BROWSER_BROWSER_MAIN_PARTS_H_
 #define CONTENT_PUBLIC_BROWSER_BROWSER_MAIN_PARTS_H_
 
 #include "content/common/content_export.h"
 
 namespace content {
@@ skipping 73 matching lines @@
   // May set |result_code|, which will be returned by |BrowserMain()|.
   virtual bool MainMessageLoopRun(int* result_code);
 
   // This happens after the main message loop has stopped, but before
   // threads are stopped.
   virtual void PostMainMessageLoopRun() {}
 
   // Called as the very last part of shutdown, after threads have been
   // stopped and destroyed.
   virtual void PostDestroyThreads() {}
+
+  // Called when shutdown is about to begin.
+  virtual void PreShutdown() {}

[jochen (gone - plz use gerrit), 2017/01/12 08:35:02]

nit. can you move that up to before PostDestroyThreads, so the methods are in
the order of expected calls

[bcwhite, 2017/01/12 17:47:03]

Done.

 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_BROWSER_MAIN_PARTS_H_