Add initial version of retainers heap profile.

src/log.cc

 // Copyright 2009 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 879 matching lines @@
   if (!Log::IsEnabled() || !FLAG_log_gc) return;
   LogMessageBuilder msg;
   msg.Append("heap-js-cons-item,%s,%d,%d\n",
              constructor[0] != '\0' ? constructor : "(anonymous)",
              number, bytes);
   msg.WriteToLogFile();
 #endif
 }
 
 
+void Logger::HeapSampleJSRetainersEvent(const char* event) {
+#ifdef ENABLE_LOGGING_AND_PROFILING
+  if (!Log::IsEnabled() || !FLAG_log_gc) return;
+  LogMessageBuilder msg;
+  msg.Append("heap-js-ret-item,%s\n", event);
+  msg.WriteToLogFile();
+#endif
+}
+
+
 void Logger::DebugTag(const char* call_site_tag) {
 #ifdef ENABLE_LOGGING_AND_PROFILING
   if (!Log::IsEnabled() || !FLAG_log) return;
   LogMessageBuilder msg;
   msg.Append("debug-tag,%s\n", call_site_tag);
   msg.WriteToLogFile();
 #endif
 }
 
 
@@ skipping 338 matching lines @@
   // Otherwise, if the sliding state window computation has not been
   // started we do it now.
   if (sliding_state_window_ == NULL) {
     sliding_state_window_ = new SlidingStateWindow();
   }
 #endif
 }
 
 
 } }  // namespace v8::internal