Added support to backtrace from botton of stack to debugger protocol

src/debug-delay.js

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1425 matching lines @@
     }
     return;
   }
 
   // Default frame range to include in backtrace.
   var from_index = 0
   var to_index = kDefaultBacktraceLength;
 
   // Get the range from the arguments.
   if (request.arguments) {
-    from_index = request.arguments.fromFrame;
-    if (from_index < 0) {
-      return response.failed('Invalid frame number');
+    if (request.arguments.fromFrame) {
+      from_index = request.arguments.fromFrame;
     }
-    to_index = request.arguments.toFrame;
-    if (to_index < 0) {
+    if (request.arguments.toFrame) {
+      to_index = request.arguments.toFrame;
+    }
+    if (request.arguments.bottom) {
+      var tmp_index = total_frames - from_index;
+      from_index = total_frames - to_index
+      to_index = tmp_index;
+    }
+    if (from_index < 0 || to_index < 0) {
       return response.failed('Invalid frame number');
     }
   }
 
   // Adjust the index.
   to_index = Math.min(total_frames, to_index);
 
   if (to_index <= from_index) {
     var error = 'Invalid frame range';
     return response.failed(error);
@@ skipping 408 matching lines @@
       json += NumberToJSON_(elem);
     } else if (IS_STRING(elem)) {
       json += StringToJSON_(elem);
     } else {
       json += elem;
     }
   }
   json += ']';
   return json;
 }