[counters] adding runtime call timers for GC

src/heap/heap.cc

 // 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.
 
 #include "src/heap/heap.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/ast/scopeinfo.h"
 #include "src/base/bits.h"
@@ skipping 991 matching lines @@
   {
     tracer()->Start(collector, gc_reason, collector_reason);
     DCHECK(AllowHeapAllocation::IsAllowed());
     DisallowHeapAllocation no_allocation_during_gc;
     GarbageCollectionPrologue();
 
     {
       HistogramTimer* gc_type_timer = GCTypeTimer(collector);
       HistogramTimerScope histogram_timer_scope(gc_type_timer);
       TRACE_EVENT0("v8", gc_type_timer->name());
+      RuntimeCallTimerScope timer(

[ulan, 2016/03/23 13:59:56]

Please move this to GcTracer::Start / Stop similar to the scope and guard by the
runtime flag.

+          isolate(), &isolate()->counters()->runtime_call_stats()->GC);
 
       next_gc_likely_to_collect_more =
           PerformGarbageCollection(collector, gc_callback_flags);
     }
 
     GarbageCollectionEpilogue();
     if (collector == MARK_COMPACTOR && FLAG_track_detached_contexts) {
       isolate()->CheckDetachedContextsAfterGC();
     }
 
@@ skipping 5391 matching lines @@
 }
 
 
 // static
 int Heap::GetStaticVisitorIdForMap(Map* map) {
   return StaticVisitorBase::GetVisitorId(map);
 }
 
 }  // namespace internal
 }  // namespace v8