Delete UDPClientSocket on same thread as creation. Also refactor.

chrome/browser/extensions/api/socket/socket_api_controller.h

Index: chrome/browser/extensions/api/socket/socket_api_controller.h
diff --git a/chrome/browser/extensions/api/socket/socket_api_controller.h b/chrome/browser/extensions/api/socket/socket_api_controller.h
index f35b10a4492315a4c6fd85053afc8d94745ea1bc..57cd6ae81f8763016332028b28a301160f8eca15 100644
--- a/chrome/browser/extensions/api/socket/socket_api_controller.h
+++ b/chrome/browser/extensions/api/socket/socket_api_controller.h
@@ -10,7 +10,6 @@
 #include <map>
 
 #include "base/memory/scoped_ptr.h"
-#include "base/memory/singleton.h"
 #include "googleurl/src/gurl.h"
 #include "net/base/completion_callback.h"
 
@@ -30,12 +29,10 @@ namespace extensions {
 
 class Socket;
 
-// The SocketController singleton keeps track of all our Sockets, and provides
-// a convenient set of methods to manipulate them.
+// SocketController keeps track of a collection of Sockets and provides a
+// convenient set of methods to manipulate them.
 class SocketController {
  public:
-  static SocketController* GetInstance();
-
   SocketController();
   virtual ~SocketController();
 
@@ -74,8 +71,6 @@ class SocketController {
   // Convenience method for accessing SocketMap.
   Socket* GetSocket(int socket_id);
 
-  friend struct DefaultSingletonTraits<SocketController>;
-
   DISALLOW_COPY_AND_ASSIGN(SocketController);
 };