[heap] Add the free remainder of a black page to the free list.

src/heap/incremental-marking.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_INCREMENTAL_MARKING_H_
 #define V8_HEAP_INCREMENTAL_MARKING_H_
 
 #include "src/cancelable-task.h"
 #include "src/execution.h"
 #include "src/heap/heap.h"
@@ skipping 197 matching lines @@
   void IterateBlackObject(HeapObject* object);
 
   Heap* heap() const { return heap_; }
 
   IncrementalMarkingJob* incremental_marking_job() {
     return &incremental_marking_job_;
   }
 
   bool black_allocation() { return black_allocation_; }
 
+  void StartBlackAllocationForTesting() { StartBlackAllocation(); }
+
  private:
   class Observer : public AllocationObserver {
    public:
     Observer(IncrementalMarking& incremental_marking, intptr_t step_size)
         : AllocationObserver(step_size),
           incremental_marking_(incremental_marking) {}
 
     void Step(int bytes_allocated, Address, size_t) override {
       incremental_marking_.Step(bytes_allocated,
                                 IncrementalMarking::GC_VIA_STACK_GUARD);
@@ skipping 73 matching lines @@
   GCRequestType request_type_;
 
   IncrementalMarkingJob incremental_marking_job_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(IncrementalMarking);
 };
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_INCREMENTAL_MARKING_H_