core: make .deprecate() warn only once

src/node.js

@@ -569,21 +569,30 @@
     NativeModule._cache[this.id] = this;
   };
 
+  // Wrap a core module's method in a wrapper that will warn on first use
+  // and then return the result of invoking the original function. After
+  // first being called the original method is restored.
   NativeModule.prototype.deprecate = function(method, message) {
     var original = this.exports[method];
     var self = this;
+    var warned = false;
+    message = message || '';
 
     Object.defineProperty(this.exports, method, {
       enumerable: false,
       value: function() {
-        message = self.id + '.' + method + ' is deprecated. ' + (message || '');
+        if (!warned) {
+          warned = true;
+          message = self.id + '.' + method + ' is deprecated. ' + message;
 
-        if ((new RegExp('\\b' + self.id + '\\b')).test(process.env.NODE_DEBUG))
+          var moduleIdCheck = new RegExp('\\b' + self.id + '\\b');
+          if (moduleIdCheck.test(process.env.NODE_DEBUG))
             console.trace(message);
           else
             console.error(message);
 
           self.exports[method] = original;
+        }
         return original.apply(this, arguments);
       }
     });