Include more information in --prof log.

src/log.h

 // Copyright 2012 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 257 matching lines @@
                                  Address* stack);
   void HeapSampleStats(const char* space, const char* kind,
                        intptr_t capacity, intptr_t used);
 
   void SharedLibraryEvent(const char* library_path,
                           uintptr_t start,
                           uintptr_t end);
   void SharedLibraryEvent(const wchar_t* library_path,
                           uintptr_t start,
                           uintptr_t end);
+  
+  // ==== Events logged by --log-timer-events. ====
   void TimerEvent(const char* name, int64_t start, int64_t end);
+  void ExternalSwitch(StateTag old_tag, StateTag new_tag);
 
   class TimerEventScope {
    public:
     TimerEventScope(Isolate* isolate, const char* name)
         : isolate_(isolate), name_(name), start_(0) {
       if (FLAG_log_timer_events) start_ = OS::Ticks();
     }
 
     ~TimerEventScope() {
       if (FLAG_log_timer_events) LogTimerEvent();
@@ skipping 180 matching lines @@
   Address last_address_;
   //  Logger::TickEvent(...)
   Address prev_sp_;
   Address prev_function_;
   //  Logger::MoveEventInternal(...)
   Address prev_to_;
   //  Logger::FunctionCreateEvent(...)
   Address prev_code_;
 
   int64_t epoch_;
+  static int64_t enter_external_;
 
   friend class CpuProfiler;
 };
 
 
 // Process wide registry of samplers.
 class SamplerRegistry : public AllStatic {
  public:
   enum State {
     HAS_NO_SAMPLERS,
@@ skipping 29 matching lines @@
 // Class that extracts stack trace, used for profiling.
 class StackTracer : public AllStatic {
  public:
   static void Trace(Isolate* isolate, TickSample* sample);
 };
 
 } }  // namespace v8::internal
 
 
 #endif  // V8_LOG_H_