[heap] Hide MemoryReducer inside the heap component.

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>
 
 #include "src/allocation.h"
 #include "src/assert-scope.h"
 #include "src/globals.h"
 #include "src/heap/gc-idle-time-handler.h"
 #include "src/heap/incremental-marking.h"
 #include "src/heap/mark-compact.h"
-#include "src/heap/memory-reducer.h"
 #include "src/heap/objects-visiting.h"
 #include "src/heap/spaces.h"
 #include "src/heap/store-buffer.h"
 #include "src/list.h"
 
 namespace v8 {
 namespace internal {
 
 // Defines all the roots in Heap.
 #define STRONG_ROOT_LIST(V)                                                    \
@@ skipping 365 matching lines @@
   V(ArgumentsMarkerMap)                 \
   V(JSMessageObjectMap)                 \
   V(ForeignMap)                         \
   V(NeanderMap)                         \
   V(empty_string)                       \
   PRIVATE_SYMBOL_LIST(V)
 
 // Forward declarations.
 class HeapStats;
 class Isolate;
+class MemoryReducer;
 class WeakObjectRetainer;
 
 
 typedef String* (*ExternalStringTableUpdaterCallback)(Heap* heap,
                                                       Object** pointer);
 
 class StoreBufferRebuilder {
  public:
   explicit StoreBufferRebuilder(StoreBuffer* store_buffer)
       : store_buffer_(store_buffer) {}
@@ skipping 1795 matching lines @@
   double last_gc_time_;
 
   MarkCompactCollector mark_compact_collector_;
 
   StoreBuffer store_buffer_;
 
   IncrementalMarking incremental_marking_;
 
   GCIdleTimeHandler gc_idle_time_handler_;
 
-  MemoryReducer memory_reducer_;
+  MemoryReducer* memory_reducer_;
 
   // These two counters are monotomically increasing and never reset.
   size_t full_codegen_bytes_generated_;
   size_t crankshaft_codegen_bytes_generated_;
 
   // This counter is increased before each GC and never reset.
   // To account for the bytes allocated since the last GC, use the
   // NewSpaceAllocationCounter() function.
   size_t new_space_allocation_counter_;
 
@@ skipping 466 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_