[--prof] Adding support for RuntimeCallTimerScope based tick separation

src/counters.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_COUNTERS_H_
 #define V8_COUNTERS_H_
 
 #include "include/v8.h"
 #include "src/allocation.h"
 #include "src/base/platform/elapsed-timer.h"
@@ skipping 475 matching lines @@
   const char* name;
   int64_t count = 0;
   base::TimeDelta time;
 };
 
 // RuntimeCallTimer is used to keep track of the stack of currently active
 // timers used for properly measuring the own time of a RuntimeCallCounter.
 class RuntimeCallTimer {
  public:
   RuntimeCallTimer() {}
+  RuntimeCallCounter* counter() { return counter_; }
+  base::ElapsedTimer timer() { return timer_; }
 
  private:
   friend class RuntimeCallStats;
 
   inline void Start(RuntimeCallCounter* counter, RuntimeCallTimer* parent) {
     counter_ = counter;
     parent_ = parent;
     timer_.Start();
   }
 
@@ skipping 262 matching lines @@
   static void Leave(Isolate* isolate, RuntimeCallTimer* timer);
 
   // Set counter id for the innermost measurement. It can be used to refine
   // event kind when a runtime entry counter is too generic.
   static void CorrectCurrentCounterId(Isolate* isolate, CounterId counter_id);
 
   void Reset();
   void Print(std::ostream& os);
 
   RuntimeCallStats() { Reset(); }
+  RuntimeCallTimer* current_timer() { return current_timer_; }
 
  private:
   // Counter to track recursive time events.
   RuntimeCallTimer* current_timer_ = NULL;
 };
 
 #define TRACE_RUNTIME_CALL_STATS(isolate, counter_name) \
   do {                                                  \
     if (FLAG_runtime_call_stats) {                      \
       RuntimeCallStats::CorrectCurrentCounterId(        \
@@ skipping 443 matching lines @@
 
   explicit Counters(Isolate* isolate);
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(Counters);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COUNTERS_H_