Fix JingleThreadWrapper initialization in PNaCl plugin.

jingle/glue/thread_wrapper.h

Index: jingle/glue/thread_wrapper.h
diff --git a/jingle/glue/thread_wrapper.h b/jingle/glue/thread_wrapper.h
index 6a045bf8a365842a3698c9511303d87539a08cab..7969d2bc6af88ce7a59eff020c80b112263b872f 100644
--- a/jingle/glue/thread_wrapper.h
+++ b/jingle/glue/thread_wrapper.h
@@ -35,13 +35,15 @@ class JingleThreadWrapper : public base::MessageLoop::DestructionObserver,
   // MessageLoop is destroyed.
   static void EnsureForCurrentMessageLoop();
 
-  // Returns thread wrapper for the current thread. NULL is returned
-  // if EnsureForCurrentMessageLoop() has never been called for this
-  // thread.
+  // Creates JingleThreadWrapper for |task_runner| that runs tasks on the
+  // current thread.
+  static scoped_ptr<JingleThreadWrapper> WrapTaskRunner(
+      scoped_refptr<base::SingleThreadTaskRunner> task_runner);
+
+  // Returns thread wrapper for the current thread or nullptr if it doesn't
+  // exist.
   static JingleThreadWrapper* current();
 
-  explicit JingleThreadWrapper(
-     scoped_refptr<base::SingleThreadTaskRunner> task_runner);
   ~JingleThreadWrapper() override;
 
   // Sets whether the thread can be used to send messages
@@ -95,6 +97,9 @@ class JingleThreadWrapper : public base::MessageLoop::DestructionObserver,
   typedef std::map<int, rtc::Message> MessagesQueue;
   struct PendingSend;
 
+  explicit JingleThreadWrapper(
+     scoped_refptr<base::SingleThreadTaskRunner> task_runner);
+
   void PostTaskInternal(
       int delay_ms, rtc::MessageHandler* handler,
       uint32 message_id, rtc::MessageData* data);