Use a shared profile buffer

runtime/vm/profiler.h

 // 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.
 
 #ifndef VM_PROFILER_H_
 #define VM_PROFILER_H_
 
 #include "vm/allocation.h"
 #include "vm/code_observers.h"
 #include "vm/globals.h"
 #include "vm/thread.h"
 #include "vm/thread_interrupter.h"
 
 namespace dart {
 
 // Forward declarations.
 class JSONArray;
 class JSONStream;
 class ProfilerCodeRegionTable;
 struct Sample;
 
 // Profiler
 class Profiler : public AllStatic {
  public:
   static void InitOnce();
   static void Shutdown();
 
   static void InitProfilingForIsolate(Isolate* isolate,
-                                      bool shared_buffer = false);
+                                      bool shared_buffer = true);
   static void ShutdownProfilingForIsolate(Isolate* isolate);
 
   static void BeginExecution(Isolate* isolate);
   static void EndExecution(Isolate* isolate);
 
   static void PrintToJSONStream(Isolate* isolate, JSONStream* stream,
                                 bool full);
   static void WriteProfile(Isolate* isolate);
 
   static SampleBuffer* sample_buffer() {
@@ skipping 112 matching lines @@
   const uintptr_t original_pc_;
   const uintptr_t original_fp_;
   const uintptr_t original_sp_;
   uintptr_t lower_bound_;
 };
 
 
 }  // namespace dart
 
 #endif  // VM_PROFILER_H_