When specifying a new create histogram callback, reset all histograms so they recreate themselves o…

src/api.cc

 // 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 5205 matching lines @@
 void V8::SetCounterFunction(CounterLookupCallback callback) {
   i::Isolate* isolate = EnterIsolateIfNeeded();
   if (IsDeadCheck(isolate, "v8::V8::SetCounterFunction()")) return;
   isolate->stats_table()->SetCounterFunction(callback);
 }
 
 void V8::SetCreateHistogramFunction(CreateHistogramCallback callback) {
   i::Isolate* isolate = EnterIsolateIfNeeded();
   if (IsDeadCheck(isolate, "v8::V8::SetCreateHistogramFunction()")) return;
   isolate->stats_table()->SetCreateHistogramFunction(callback);
+  isolate->InitializeLoggingAndCounters();
+  isolate->counters()->ResetHistograms();
 }
 
 void V8::SetAddHistogramSampleFunction(AddHistogramSampleCallback callback) {
   i::Isolate* isolate = EnterIsolateIfNeeded();
   if (IsDeadCheck(isolate, "v8::V8::SetAddHistogramSampleFunction()")) return;
   isolate->stats_table()->
       SetAddHistogramSampleFunction(callback);
 }
 
 void V8::EnableSlidingStateWindow() {
@@ skipping 1282 matching lines @@
 
   v->VisitPointers(blocks_.first(), first_block_limit_);
 
   for (int i = 1; i < blocks_.length(); i++) {
     v->VisitPointers(blocks_[i], &blocks_[i][kHandleBlockSize]);
   }
 }
 
 
 } }  // namespace v8::internal