Revert 111695 - Have content/ create and destroy its own threads.

chrome/browser/io_thread.h

Index: chrome/browser/io_thread.h
===================================================================
--- chrome/browser/io_thread.h	(revision 111697)
+++ chrome/browser/io_thread.h	(working copy)
@@ -9,26 +9,13 @@
 #include <string>
 
 #include "base/basictypes.h"
-#include "base/compiler_specific.h"
-#include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "chrome/browser/net/ssl_config_service_manager.h"
 #include "chrome/browser/prefs/pref_member.h"
-#include "content/public/browser/browser_thread.h"
-#include "content/public/browser/browser_thread_delegate.h"
+#include "content/browser/browser_process_sub_thread.h"
 #include "net/base/network_change_notifier.h"
 
-// TODO(joi): Remove these in a follow-up change and IWYU in files
-// that were getting them directly or indirectly from here.
-#include "base/memory/ref_counted.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/message_loop.h"
-#include "base/message_loop_proxy.h"
-#include "base/synchronization/lock.h"
-#include "base/threading/thread.h"
-
-class BrowserProcessImpl;
 class ChromeNetLog;
 class ExtensionEventRouterForwarder;
 class MediaInternals;
@@ -56,10 +43,7 @@
 class URLSecurityManager;
 }  // namespace net
 
-// Contains state associated with, initialized and cleaned up on, and
-// primarily used on, the IO thread.  Also acts as a convenience
-// accessor to the Thread object for the IO thread.
-class IOThread : public content::BrowserThreadDelegate {
+class IOThread : public content::BrowserProcessSubThread {
  public:
   struct Globals {
     Globals();
@@ -125,37 +109,26 @@
   // called on the IO thread.
   void ClearHostCache();
 
-  // Convenience method similar to base::Thread, giving access to the
-  // actual IO thread.
-  // TODO(joi): Remove this in follow-up changes.
-  MessageLoop* message_loop() const;
-
- private:
-  // BrowserThreadDelegate implementation, runs on the IO thread.
-  // This handles initialization and destruction of state that must
-  // live on the IO thread.
+ protected:
   virtual void Init() OVERRIDE;
   virtual void CleanUp() OVERRIDE;
 
+ private:
   // Provide SystemURLRequestContextGetter with access to
   // InitSystemRequestContext().
   friend class SystemURLRequestContextGetter;
 
-  // Global state must be initialized on the IO thread, then this
-  // method must be invoked on the UI thread.
-  void InitSystemRequestContext();
-
-  // Lazy initialization of system request context for
-  // SystemURLRequestContextGetter. To be called on IO thread only
-  // after global state has been initialized on the IO thread, and
-  // SystemRequestContext state has been initialized on the UI thread.
-  void InitSystemRequestContextOnIOThread();
-
   static void RegisterPrefs(PrefService* local_state);
 
   net::HttpAuthHandlerFactory* CreateDefaultAuthHandlerFactory(
       net::HostResolver* resolver);
 
+  void InitSystemRequestContext();
+
+  // Lazy initialization of system request context for
+  // SystemURLRequestContextGetter. To be called on IO thread.
+  void InitSystemRequestContextOnIOThread();
+
   // Returns an SSLConfigService instance.
   net::SSLConfigService* GetSSLConfigService();