bug 905410 - remove most remaining usage of nspr atomics outside of xpcom/ r=ehsan

netwerk/protocol/websocket/WebSocketChannel.cpp

@@ -35,12 +35,12 @@
 #include "nsAlgorithm.h"
 #include "nsProxyRelease.h"
 #include "nsNetUtil.h"
+#include "mozilla/Atomics.h"
 #include "mozilla/Attributes.h"
 #include "TimeStamp.h"
 #include "mozilla/Telemetry.h"
 
 #include "plbase64.h"
-#include "pratom.h"
 #include "prmem.h"
 #include "prnetdb.h"
 #include "prbit.h"
@@ -424,12 +424,12 @@ public:
 
   void IncrementSessionCount()
   {
-    PR_ATOMIC_INCREMENT(&mSessionCount);
+    mSessionCount++;
   }
 
   void DecrementSessionCount()
   {
-    PR_ATOMIC_DECREMENT(&mSessionCount);
+    mSessionCount--;
   }
 
   int32_t SessionCount()
@@ -468,7 +468,7 @@ private:
 
   // SessionCount might be decremented from the main or the socket
   // thread, so manage it with atomic counters
-  int32_t               mSessionCount;
+  Atomic<int32_t>               mSessionCount;
 
   // Queue for websockets that have not completed connecting yet.
   // The first nsOpenConn with a given address will be either be