7155963: Deadlock in SystemFlavorMap.getFlavorsForNative and SunToolkit.awtLock

Reviewed-by: ant, serb

src/solaris/classes/sun/awt/X11/XClipboard.java

 /*
- * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -281,6 +281,11 @@ public final class XClipboard extends SunClipboard implements OwnershipListener
             }
         }
 
-        checkChange(formats);
+        XToolkit.awtUnlock();
+        try {
+            checkChange(formats);
+        } finally {
+            XToolkit.awtLock();
+        }
     }
 }