Reland of [counters] adding runtime call timers for GC

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 510 matching lines @@
   RuntimeCallTimer* parent_;
   base::ElapsedTimer timer_;
 };
 
 struct RuntimeCallStats {
   // Dummy counter for the unexpected stub miss.
   RuntimeCallCounter UnexpectedStubMiss =
       RuntimeCallCounter("UnexpectedStubMiss");
   // Counter for runtime callbacks into JavaScript.
   RuntimeCallCounter ExternalCallback = RuntimeCallCounter("ExternalCallback");
+  RuntimeCallCounter GC = RuntimeCallCounter("GC");
 #define CALL_RUNTIME_COUNTER(name, nargs, ressize) \
   RuntimeCallCounter Runtime_##name = RuntimeCallCounter(#name);
   FOR_EACH_INTRINSIC(CALL_RUNTIME_COUNTER)
 #undef CALL_RUNTIME_COUNTER
 #define CALL_BUILTIN_COUNTER(name, type) \
   RuntimeCallCounter Builtin_##name = RuntimeCallCounter(#name);
   BUILTIN_LIST_C(CALL_BUILTIN_COUNTER)
 #undef CALL_BUILTIN_COUNTER
 
   // Counter to track recursive time events.
@@ skipping 435 matching lines @@
 
   explicit Counters(Isolate* isolate);
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(Counters);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COUNTERS_H_