[heap] Remove obsolete Heap::sweep_generation field.

src/heap/heap.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_HEAP_HEAP_H_
 #define V8_HEAP_HEAP_H_
 
 #include <cmath>
 #include <map>
 
@@ skipping 931 matching lines @@
   Object* encountered_weak_collections() const {
     return encountered_weak_collections_;
   }
 
   void set_encountered_weak_cells(Object* weak_cell) {
     encountered_weak_cells_ = weak_cell;
   }
   Object* encountered_weak_cells() const { return encountered_weak_cells_; }
 
   // Number of mark-sweeps.
-  unsigned int ms_count() { return ms_count_; }
+  int ms_count() const { return ms_count_; }
 
   // Iterates over all roots in the heap.
   void IterateRoots(ObjectVisitor* v, VisitMode mode);
   // Iterates over all strong roots in the heap.
   void IterateStrongRoots(ObjectVisitor* v, VisitMode mode);
   // Iterates over entries in the smi roots list.  Only interesting to the
   // serializer/deserializer, since GC does not care about smis.
   void IterateSmiRoots(ObjectVisitor* v);
   // Iterates over all the other roots in the heap.
   void IterateWeakRoots(ObjectVisitor* v, VisitMode mode);
@@ skipping 449 matching lines @@
   }
 
   StoreBuffer* store_buffer() { return &store_buffer_; }
 
   IncrementalMarking* incremental_marking() { return &incremental_marking_; }
 
   ExternalStringTable* external_string_table() {
     return &external_string_table_;
   }
 
-  // Returns the current sweep generation.
-  int sweep_generation() { return sweep_generation_; }
-
   bool concurrent_sweeping_enabled() { return concurrent_sweeping_enabled_; }
 
   inline Isolate* isolate();
 
   void CallGCPrologueCallbacks(GCType gc_type, GCCallbackFlags flags);
   void CallGCEpilogueCallbacks(GCType gc_type, GCCallbackFlags flags);
 
   inline bool OldGenerationAllocationLimitReached();
 
   void QueueMemoryChunkForFree(MemoryChunk* chunk);
@@ skipping 260 matching lines @@
   intptr_t max_executable_size_;
   intptr_t maximum_committed_;
 
   // For keeping track of how much data has survived
   // scavenge since last new space expansion.
   int survived_since_last_expansion_;
 
   // ... and since the last scavenge.
   int survived_last_scavenge_;
 
-  // For keeping track on when to flush RegExp code.
-  int sweep_generation_;
-
   int always_allocate_scope_depth_;
 
   // For keeping track of context disposals.
   int contexts_disposed_;
 
   int global_ic_age_;
 
   int scan_on_scavenge_pages_;
 
   NewSpace new_space_;
@@ skipping 991 matching lines @@
   DisallowHeapAllocation no_allocation;  // i.e. no gc allowed.
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG
 }
 }  // namespace v8::internal
 
 #endif  // V8_HEAP_HEAP_H_