G1: Use SoftMaxHeapSize to guide GC heuristics

*** 43,60 ****
    // Ratio check data for determining if heap growth is necessary.
    uint _ratio_over_threshold_count;
    double _ratio_over_threshold_sum;
    uint _pauses_since_start;
  
  
  protected:
    G1HeapSizingPolicy(const G1CollectedHeap* g1h, const G1Analytics* analytics);
  public:
  
    // If an expansion would be appropriate, because recent GC overhead had
    // exceeded the desired limit, return an amount to expand by.
!   virtual size_t expansion_amount();
  
    // Clear ratio tracking data used by expansion_amount().
    void clear_ratio_check_data();
  
    static G1HeapSizingPolicy* create(const G1CollectedHeap* g1h, const G1Analytics* analytics);
--- 43,65 ----
    // Ratio check data for determining if heap growth is necessary.
    uint _ratio_over_threshold_count;
    double _ratio_over_threshold_sum;
    uint _pauses_since_start;
  
+   // Mininum heap capacity after last concurrent mark
+   size_t _minimum_desired_bytes_after_last_cm;
+ 
  
  protected:
    G1HeapSizingPolicy(const G1CollectedHeap* g1h, const G1Analytics* analytics);
  public:
  
    // If an expansion would be appropriate, because recent GC overhead had
    // exceeded the desired limit, return an amount to expand by.
!   virtual size_t expansion_amount_after_young_collection();
!   virtual size_t expansion_amount_after_concurrent_mark();
!   virtual size_t shrink_amount_after_mixed_collections();
  
    // Clear ratio tracking data used by expansion_amount().
    void clear_ratio_check_data();
  
    static G1HeapSizingPolicy* create(const G1CollectedHeap* g1h, const G1Analytics* analytics);