Introduce SynchronizedScope to allow heap access from compiler thread.

tools/profviz/composer.js

 // Copyright 2013 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 85 matching lines @@
       'V8.Execute':
         new TimerEvent("execution", "#000000", false, 0),
       'V8.External':
         new TimerEvent("external", "#3399FF", false, 0),
       'V8.CompileFullCode':
         new TimerEvent("compile unopt", "#CC0000",  true, 0),
       'V8.RecompileSynchronous':
         new TimerEvent("recompile sync", "#CC0044",  true, 0),
       'V8.RecompileConcurrent':
         new TimerEvent("recompile async", "#CC4499", false, 1),
+      'V8.RecompileSynchronized':
+        new TimerEvent("recompile block", "#991166", true, 0),
       'V8.CompileEval':
         new TimerEvent("compile eval", "#CC4400",  true, 0),
       'V8.Parse':
         new TimerEvent("parse", "#00CC00",  true, 0),
       'V8.PreParse':
         new TimerEvent("preparse", "#44CC00",  true, 0),
       'V8.ParseLazy':
         new TimerEvent("lazy parse", "#00CC44",  true, 0),
       'V8.GCScavenger':
         new TimerEvent("gc scavenge", "#0044CC",  true, 0),
@@ skipping 406 matching lines @@
     output("plot '-' using 1:2 axes x1y2 with impulses ls 1");
     for (var i = 0; i < execution_pauses.length; i++) {
       var pause = execution_pauses[i];
       output(pause.end + " " + pause.duration());
       obj_index++;
     }
     output("e");
     return obj_index;
   };
 }