Wholesale move of debugger sources to content.

content/browser/debugger/manual_tests/resources/fib.js

 function fib(n) {
   return n < 2 ? 1 : fib(n - 1) + fib(n - 2);
 }
 
 function eternal_fib() {
   var started = Date.now();
   while(true) {
     fib(20);
     // Make page responsive by making a break every 100 ms.
     if (Date.now() - started >= 100) {
       setTimeout(eternal_fib, 0);
       return;
     }
   }
 }
 
 function run_fib() {
   // Let the page do initial rendering, then go.
   setTimeout(eternal_fib, 200);
 }