Mark shouldMarkObject(), arenaForNormalPage() accessors as const.

third_party/WebKit/Source/platform/heap/HeapPage.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 476 matching lines @@
 #endif
     size_t size() override { return blinkPageSize; }
     static size_t pageHeaderSize()
     {
         // Compute the amount of padding we have to add to a header to make
         // the size of the header plus the padding a multiple of 8 bytes.
         size_t paddingSize = (sizeof(NormalPage) + allocationGranularity - (sizeof(HeapObjectHeader) % allocationGranularity)) % allocationGranularity;
         return sizeof(NormalPage) + paddingSize;
     }
 
-    NormalPageArena* arenaForNormalPage();
+    inline NormalPageArena* arenaForNormalPage() const;
 
 private:
     HeapObjectHeader* findHeaderFromAddress(Address);
     void populateObjectStartBitMap();
 
     bool m_objectStartBitMapComputed;
     uint8_t m_objectStartBitMap[reservedForObjectBitMap];
 };
 
 // Large allocations are allocated as separate objects and linked in a list.
@@ skipping 410 matching lines @@
         Address result = headerAddress + sizeof(HeapObjectHeader);
         ASSERT(!(reinterpret_cast<uintptr_t>(result) & allocationMask));
 
         SET_MEMORY_ACCESSIBLE(result, allocationSize - sizeof(HeapObjectHeader));
         ASSERT(findPageFromAddress(headerAddress + allocationSize - 1));
         return result;
     }
     return outOfLineAllocate(allocationSize, gcInfoIndex);
 }
 
+inline NormalPageArena* NormalPage::arenaForNormalPage() const
+{
+    return static_cast<NormalPageArena*>(arena());
+}
+
 } // namespace blink
 
 #endif // HeapPage_h