Have content/ create and destroy its own threads.

chrome/browser/chrome_browser_parts_gtk.h

Index: chrome/browser/chrome_browser_parts_gtk.h
diff --git a/chrome/browser/chrome_browser_parts_gtk.h b/chrome/browser/chrome_browser_parts_gtk.h
index e824f3c6f48d6c7b7dba03a0924ec21c17397c12..a6f9c61e70f0d7a69e7a0effbd7b87be009c023f 100644
--- a/chrome/browser/chrome_browser_parts_gtk.h
+++ b/chrome/browser/chrome_browser_parts_gtk.h
@@ -9,20 +9,29 @@
 #pragma once
 
 #include "base/compiler_specific.h"
+#include "content/public/browser/browser_thread.h"
 #include "content/public/browser/browser_main_parts.h"
 
+namespace content {
+class IOThreadDelegate;
+}
+
 class ChromeBrowserPartsGtk : public content::BrowserMainParts {
  public:
   ChromeBrowserPartsGtk();
 
   virtual void PreEarlyInitialization() OVERRIDE;
   virtual void PostEarlyInitialization() OVERRIDE;
-  virtual void ToolkitInitialized() OVERRIDE;
   virtual void PreMainMessageLoopStart() OVERRIDE;
+  virtual void ToolkitInitialized() OVERRIDE;
   virtual void PostMainMessageLoopStart() OVERRIDE;
-  virtual void PreMainMessageLoopRun() OVERRIDE;
+  virtual content::IOThreadDelegate* PreMainMessageLoopRun() OVERRIDE;
+  virtual void PreMainMessageLoopRunThreadsCreated() OVERRIDE;
   virtual bool MainMessageLoopRun(int* result_code) OVERRIDE;
   virtual void PostMainMessageLoopRun() OVERRIDE;
+  virtual void PreStopThread(content::BrowserThread::ID) OVERRIDE;
+  virtual void PostStopThread(content::BrowserThread::ID) OVERRIDE;
+  virtual void FinalCleanup() OVERRIDE;
 
   static void ShowMessageBox(const char* message);