Fix compiler stats timer code

runtime/vm/object.cc

 // Copyright (c) 2012, 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.
 
 #include "vm/object.h"
 
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/bigint_operations.h"
 #include "vm/bootstrap.h"
@@ skipping 3653 matching lines @@
 
 
 void Script::Tokenize(const String& private_key) const {
   const TokenStream& tkns = TokenStream::Handle(tokens());
   if (!tkns.IsNull()) {
     // Already tokenized.
     return;
   }
 
   // Get the source, scan and allocate the token stream.
-  if (FLAG_compiler_stats) {
-    CompilerStats::scanner_timer.Start();
-  }
+  TimerScope timer(FLAG_compiler_stats, &CompilerStats::scanner_timer);
   const String& src = String::Handle(source());
   Scanner scanner(src, private_key);
   set_tokens(TokenStream::Handle(TokenStream::New(scanner.GetStream())));
   if (FLAG_compiler_stats) {
-    CompilerStats::scanner_timer.Stop();
     CompilerStats::src_length += src.Length();
   }
 }
 
 
 void Script::GetTokenLocation(intptr_t token_index,
                               intptr_t* line,
                               intptr_t* column) const {
   const String& src = String::Handle(source());
   const String& dummy_key = String::Handle(String::New(""));
@@ skipping 4019 matching lines @@
   const String& str = String::Handle(pattern());
   const char* format = "JSRegExp: pattern=%s flags=%s";
   intptr_t len = OS::SNPrint(NULL, 0, format, str.ToCString(), Flags());
   char* chars = reinterpret_cast<char*>(
       Isolate::Current()->current_zone()->Allocate(len + 1));
   OS::SNPrint(chars, (len + 1), format, str.ToCString(), Flags());
   return chars;
 }
 
 }  // namespace dart