How to know in which file that defined a js global var in chrome console?

Question

How to find out which file and line a variable was defined in using google chrome console?

For example, the variable Native (from MooTools) has been def

Answer 1

Native is defined in core.js line 437

var Native = this.Native = function(properties){
    return new Type(properties.name, properties.initialize);
};

Native.type = Type.type;

Native.implement = function(objects, methods){
    for (var i = 0; i < objects.length; i++) objects[i].implement(methods);
    return Native;
};

https://github.com/mootools/mootools-core/blob/master/Source/Core/Core.js#L437

a quick file search for a = assignment is almost always the way to go