Change halfway-to-the-max GC trigger to measure committed pages, not allocated objects

src/heap/mark-compact.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_MARK_COMPACT_H_
 #define V8_HEAP_MARK_COMPACT_H_
 
 #include "src/base/bits.h"
 #include "src/heap/spaces.h"
 
@@ skipping 618 matching lines @@
 
   void MigrateObject(HeapObject* dst, HeapObject* src, int size,
                      AllocationSpace to_old_space);
 
   bool TryPromoteObject(HeapObject* object, int object_size);
 
   void InvalidateCode(Code* code);
 
   void ClearMarkbits();
 
-  bool abort_incremental_marking() const { return abort_incremental_marking_; }
+  bool incremental_marking_abort_requested() const {
+    return incremental_marking_abort_requested_;
+  }
 
   bool is_compacting() const { return compacting_; }
 
   MarkingParity marking_parity() { return marking_parity_; }
 
   // Concurrent and parallel sweeping support. If required_freed_bytes was set
   // to a value larger than 0, then sweeping returns after a block of at least
   // required_freed_bytes was freed. If required_freed_bytes was set to zero
   // then the whole given space is swept. It returns the size of the maximum
   // continuous freed memory chunk.
@@ skipping 68 matching lines @@
     UPDATE_POINTERS,
     RELOCATE_OBJECTS
   };
 
   // The current stage of the collector.
   CollectorState state_;
 #endif
 
   bool reduce_memory_footprint_;
 
-  bool abort_incremental_marking_;
+  bool incremental_marking_abort_requested_;
 
   MarkingParity marking_parity_;
 
   // True if we are collecting slots to perform evacuation from evacuation
   // candidates.
   bool compacting_;
 
   bool was_marked_incrementally_;
 
   // True if concurrent or parallel sweeping is currently in progress.
@@ skipping 239 matching lines @@
  private:
   MarkCompactCollector* collector_;
 };
 
 
 const char* AllocationSpaceName(AllocationSpace space);
 }
 }  // namespace v8::internal
 
 #endif  // V8_HEAP_MARK_COMPACT_H_