Fix several memory leaks. Also, use monitors around sensetive structures.

git-svn-id: svn://10.0.0.236/trunk@169795 18797224-902f-48f8-a5cc-f745e15eee43

mozilla/extensions/java/xpcom/nsJavaXPTCStub.h

@@ -77,6 +77,10 @@ public:
   // getter for mJavaObject
   jobject GetJavaObject();
 
+  // Deletes the strong global ref for the Java object, so it can be garbage
+  // collected if necessary.  See DestroyXPTCMappingEnum().
+  void DeleteStrongRef();
+
 private:
   NS_IMETHOD_(nsrefcnt) AddRefInternal();
   NS_IMETHOD_(nsrefcnt) ReleaseInternal();