Adds clearer function to create rtc::Thread without Physical SocketServer

webrtc/base/thread.h

Index: webrtc/base/thread.h
diff --git a/webrtc/base/thread.h b/webrtc/base/thread.h
index df5a686952f4efe49ea3873a844d245016b8c218..7928c934d4dc085fc39caca8cbdaab24b3def807 100644
--- a/webrtc/base/thread.h
+++ b/webrtc/base/thread.h
@@ -99,7 +99,8 @@ class Thread : public MessageQueue {
   // DoInit() from their constructor to prevent races with the
   // MessageQueueManager already using the object while the vtable is still
   // being created.
-  explicit Thread(SocketServer* ss = nullptr, bool init_queue = true);
+  Thread();
+  explicit Thread(SocketServer* ss);

[tommi, 2016/04/27 12:45:25]

Down the line, I think it would be good if the socket server dependency could be
moved to a derived class, e.g. SocketServerThread.

[danilchap, 2016/04/27 15:08:55]

I see this cl as a small step towards that goal.

 
   // NOTE: ALL SUBCLASSES OF Thread MUST CALL Stop() IN THEIR DESTRUCTORS (or
   // guarantee Stop() is explicitly called before the subclass is destroyed).
@@ -107,6 +108,8 @@ class Thread : public MessageQueue {
   // vtable, and the Thread::PreRun calling the virtual method Run().
   ~Thread() override;
 
+  static std::unique_ptr<Thread> CreateWithSocketServer();
+  static std::unique_ptr<Thread> Create();
   static Thread* Current();
 
   // Used to catch performance regressions. Use this to disallow blocking calls
@@ -224,6 +227,9 @@ class Thread : public MessageQueue {
   void UnwrapCurrent();
 
  protected:
+  Thread(SocketServer* ss, bool init_queue);
+  Thread(std::unique_ptr<SocketServer> ss, bool init_queue);
+
   // Same as WrapCurrent except that it never fails as it does not try to
   // acquire the synchronization access of the thread. The caller should never
   // call Stop() or Join() on this thread.
@@ -291,7 +297,7 @@ class Thread : public MessageQueue {
 
 class AutoThread : public Thread {
  public:
-  explicit AutoThread(SocketServer* ss = nullptr);
+  AutoThread();
   ~AutoThread() override;
 
  private: