Add flag to control profiler rate

tools/tracesummary.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 // Print a summary of a profile trace.
 
 import 'dart:convert';
 import 'dart:io';
 
 class TraceSymbol {
@@ skipping 50 matching lines @@
     var symbol = _stack.last;
     if (symbol.name != name) {
       throw new StateError('$name not found at top of stack.');
     }
     if ((_stack.length > 1) && (_marked == false)) {
       // We are transitioning from the sequence of begins to the sequence
       // of ends. Mark the symbols on the stack.
       _marked = true;
       _totalSamples++;
       // Mark all symbols except the top with an inclusive tick.
-      for (int i = 1; i < _stack.length - 1; i++) {
+      for (int i = 1; i < _stack.length; i++) {
         _stack[i].inclusive++;
       }
       _stack.last.exclusive++;
     }
     _stack.removeLast();
   }
 
   void _processEvents(List events) {
     for (var i = 0; i < events.length; i++) {
       Map event = events[i];
@@ skipping 72 matching lines @@
     return;
   }
   String input = arguments[0];
   int numSymbols = 10;
   if (arguments.length >= 2) {
     numSymbols = int.parse(arguments[1]);
   }
   TraceSummary ts = new TraceSummary(numSymbols);
   ts.summarize(input);
 }