DevTools: Make StepInto work across script boundaries and Blink process tasks.

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 114 matching lines @@
     }
 }
 
 Framework.throwFrameworkExceptionAndCatch = function()
 {
     try {
         Framework.throwFrameworkException();
     } catch(e) {
     }
 }
+
+Framework.scheduleUntilDone = function(callback, delay)
+{
+    Framework.schedule(Framework_scheduleUntilDone, delay);
+
+    function Framework_scheduleUntilDone()
+    {
+        if (callback && callback())
+            return;
+        Framework.schedule(Framework_scheduleUntilDone, delay);
+    }
+}