Add a flag to deoptimize all functions every n garbage collections.

src/heap.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 2277 matching lines @@
 
   int number_idle_notifications_;
   unsigned int last_idle_notification_gc_count_;
   bool last_idle_notification_gc_count_init_;
 
   int mark_sweeps_since_idle_round_started_;
   int ms_count_at_last_idle_notification_;
   unsigned int gc_count_at_last_idle_gc_;
   int scavenges_since_last_idle_round_;
 
+  // If the --deopt_every_n_garbage_collections flag is set to a positive value,
+  // this variable holds the number of garbage collections since the last
+  // deoptimization triggered by garbage collection.
+  int gcs_since_last_deopt_;
+
 #ifdef VERIFY_HEAP
   int no_weak_embedded_maps_verification_scope_depth_;
 #endif
 
   static const int kMaxMarkSweepsInIdleRound = 7;
   static const int kIdleScavengeThreshold = 5;
 
   // Shared state read by the scavenge collector and set by ScavengeObject.
   PromotionQueue promotion_queue_;
 
@@ skipping 707 matching lines @@
   AssertNoAllocation no_alloc;  // i.e. no gc allowed.
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_H_