Move autowrap from ThreadManager constructor to Thread::Current.

webrtc/base/thread.h

Index: webrtc/base/thread.h
diff --git a/webrtc/base/thread.h b/webrtc/base/thread.h
index 01c80501c8010a2cfd2f39230abf1f9af28f3f34..e9bb3249ea809f9b963d58a3a65d932a3e2d3be7 100644
--- a/webrtc/base/thread.h
+++ b/webrtc/base/thread.h
@@ -23,6 +23,7 @@
 #include "webrtc/base/constructormagic.h"
 #include "webrtc/base/event.h"
 #include "webrtc/base/messagequeue.h"
+#include "webrtc/base/platform_thread_types.h"
 
 #if defined(WEBRTC_WIN)
 #include "webrtc/base/win32.h"
@@ -36,9 +37,7 @@ class ThreadManager {
  public:
   static const int kForever = -1;
 
-  ThreadManager();
-  ~ThreadManager();
-
+  // Singleton, constructor and destructor are private.
   static ThreadManager* Instance();
 
   Thread* CurrentThread();
@@ -60,7 +59,12 @@ class ThreadManager {
   Thread *WrapCurrentThread();
   void UnwrapCurrentThread();
 
+  bool IsMainThread();
+
  private:
+  ThreadManager();
+  ~ThreadManager();
+
 #if defined(WEBRTC_POSIX)
   pthread_key_t key_;
 #endif
@@ -69,6 +73,9 @@ class ThreadManager {
   DWORD key_;
 #endif
 
+  // The thread to potentially autowrap.
+  PlatformThreadRef main_thread_ref_;
+
   RTC_DISALLOW_COPY_AND_ASSIGN(ThreadManager);
 };
 
@@ -123,9 +130,7 @@ class LOCKABLE Thread : public MessageQueue {
     const bool previous_state_;
   };
 
-  bool IsCurrent() const {
-    return Current() == this;
-  }
+  bool IsCurrent() const;
 
   // Sleeps the calling thread for the specified number of milliseconds, during
   // which time no processing is performed. Returns false if sleeping was