Revert of DevTools: Debugger StepInto/Out/Over initiated from a framework should not black-box it.

LayoutTests/inspector/sources/debugger/resources/framework.js

 // A framework for testing.
 
 var Framework = {};
 
 Framework.safeRun = function(callback, onSuccess, onException, breakOnUncaught)
 {
     try {
         callback();
         if (onSuccess)
             Framework.safeRun(onSuccess, undefined, onException, breakOnUncaught);
@@ skipping 58 matching lines @@
 
 Framework.appendChild = function(parent, child)
 {
     parent.appendChild(child);
 }
 
 Framework.sendXHR = function(url)
 {
     var request = new XMLHttpRequest();
     request.open("GET", url, true);
-    try { request.send(); } catch (e) {}
+    request.send();
 }
 
 Framework.addEventListener = function(element, eventType, listener, capture)
 {
     function Framework_eventListener()
     {
         if (listener)
             listener();
     }
 
@@ skipping 13 matching lines @@
     function Framework_bound(var_args)
     {
         return func.apply(thisObject, args.concat(Array.prototype.slice.call(arguments)));
     }
     Framework_bound.toString = function()
     {
         return "Framework_bound: " + func;
     };
     return Framework_bound;
 }