Remove the dependency to ws2_32.dll from talk_base::ThreadManager and talk_base::Thread.

third_party/libjingle/overrides/talk/base/thread.h

Index: third_party/libjingle/overrides/talk/base/thread.h
===================================================================
--- third_party/libjingle/overrides/talk/base/thread.h	(revision 123769)
+++ third_party/libjingle/overrides/talk/base/thread.h	(working copy)
@@ -116,9 +116,12 @@
 
 class Thread : public MessageQueue {
  public:
-  Thread(SocketServer* ss = NULL);
+  Thread();
+  explicit Thread(SocketServer* ss);
   virtual ~Thread();
 
+  void Construct();
+
   static inline Thread* Current() {
     return ThreadManager::Instance()->CurrentThread();
   }