Prevent data race in MessageQueue.

webrtc/base/messagequeue.h

Index: webrtc/base/messagequeue.h
diff --git a/webrtc/base/messagequeue.h b/webrtc/base/messagequeue.h
index a7991a8923ad407c216c63542445077df50d2896..360c272c747a439115f8a93e9db1783db595a1bb 100644
--- a/webrtc/base/messagequeue.h
+++ b/webrtc/base/messagequeue.h
@@ -24,9 +24,11 @@
 #include "webrtc/base/messagehandler.h"
 #include "webrtc/base/scoped_ptr.h"
 #include "webrtc/base/scoped_ref_ptr.h"
+#include "webrtc/base/sharedexclusivelock.h"
 #include "webrtc/base/sigslot.h"
 #include "webrtc/base/socketserver.h"
 #include "webrtc/base/timeutils.h"
+#include "webrtc/base/thread_annotations.h"
 
 namespace rtc {
 
@@ -181,7 +183,7 @@ class MessageQueue {
   // calling Clear on the object from a different thread.
   virtual ~MessageQueue();
 
-  SocketServer* socketserver() { return ss_; }
+  SocketServer* socketserver();
   void set_socketserver(SocketServer* ss);
 
   // Note: The behavior of MessageQueue has changed.  When a MQ is stopped,
@@ -261,16 +263,17 @@ class MessageQueue {
   void DoDestroy();
 
   // The SocketServer is not owned by MessageQueue.
-  SocketServer* ss_;
+  SocketServer* ss_ GUARDED_BY(ss_lock_);
   // If a server isn't supplied in the constructor, use this one.
   scoped_ptr<SocketServer> default_ss_;
   bool fStop_;
   bool fPeekKeep_;
   Message msgPeek_;
-  MessageList msgq_;
-  PriorityQueue dmsgq_;
-  uint32_t dmsgq_next_num_;
+  MessageList msgq_ GUARDED_BY(crit_);
+  PriorityQueue dmsgq_ GUARDED_BY(crit_);
+  uint32_t dmsgq_next_num_ GUARDED_BY(crit_);
   CriticalSection crit_;
+  SharedExclusiveLock ss_lock_;
   bool fInitialized_;
   bool fDestroyed_;