Have content/ create and destroy its own threads.

content/browser/browser_main_loop.h

Index: content/browser/browser_main_loop.h
diff --git a/content/browser/browser_main_loop.h b/content/browser/browser_main_loop.h
index d02d578595dd60ac5379801768b439a3f98e206c..3038332a3f7366e62ca12cf52709ec83d0dfeb96 100644
--- a/content/browser/browser_main_loop.h
+++ b/content/browser/browser_main_loop.h
@@ -8,6 +8,7 @@
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
+#include "content/browser/browser_process_sub_thread.h"
 
 class CommandLine;
 class HighResolutionTimerManager;
@@ -25,6 +26,7 @@ class NetworkChangeNotifier;
 namespace content {
 
 class BrowserMainParts;
+class BrowserShutdownImpl;
 class BrowserThreadImpl;
 struct MainFunctionParams;
 
@@ -46,6 +48,13 @@ class BrowserMainLoop {
   int GetResultCode() const { return result_code_; }
 
  private:
+  // For ShutdownThreadsAndCleanUp.
+  friend class BrowserShutdownImpl;
+
+  // Performs the shutdown sequence, starting with PostMainMessageLoopRun
+  // through stopping threads to PostDestroyThreads.
+  void ShutdownThreadsAndCleanUp();
+
   void InitializeMainThread();
 
   // Members initialized on construction ---------------------------------------
@@ -69,6 +78,14 @@ class BrowserMainLoop {
   // Members initialized in |InitializeMainThread()| ---------------------------
   // This must get destroyed before other threads that are created in parts_.
   scoped_ptr<BrowserThreadImpl> main_thread_;
+  scoped_ptr<BrowserProcessSubThread> io_thread_;
+  scoped_ptr<BrowserProcessSubThread> file_thread_;
+  scoped_ptr<BrowserProcessSubThread> db_thread_;
+  scoped_ptr<BrowserProcessSubThread> process_launcher_thread_;
+  scoped_ptr<BrowserProcessSubThread> cache_thread_;
+#if defined(OS_CHROMEOS)
+  scoped_ptr<BrowserProcessSubThread> web_socket_proxy_thread_;
+#endif
 
   DISALLOW_COPY_AND_ASSIGN(BrowserMainLoop);
 };