Remove orphaned pages from Oilpan

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

 // Copyright 2015 The Chromium 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 PagePool_h
 #define PagePool_h
 
 #include "platform/heap/ThreadState.h"
 #include "wtf/Allocator.h"
 #include "wtf/ThreadingPrimitives.h"
 
 namespace blink {
 
-class BasePage;
 class PageMemory;
 
 template <typename DataType>

[sof, 2017/02/08 11:58:08]

we can drop the parameterization of PagePool<> now.

[haraken, 2017/02/08 11:59:54]

Good point. Let me do that in a follow-up.

 class PagePool {
   USING_FAST_MALLOC(PagePool);
 
  protected:
   PagePool() {
     for (int i = 0; i < BlinkGC::NumberOfArenas; ++i)
       m_pool[i] = nullptr;
   }
 
   class PoolEntry {
@@ skipping 20 matching lines @@
 class FreePagePool : public PagePool<PageMemory> {
  public:
   ~FreePagePool();
   void addFreePage(int, PageMemory*);
   PageMemory* takeFreePage(int);
 
  private:
   Mutex m_mutex[BlinkGC::NumberOfArenas];
 };
 
-class OrphanedPagePool : public PagePool<BasePage> {
- public:
-  // The orphaned zap value must be zero in the lowest bits to allow for
-  // using the mark bit when tracing.
-  static const uint8_t orphanedZapValue = 0xdc;
-
-  ~OrphanedPagePool();
-  void addOrphanedPage(int, BasePage*);
-  void decommitOrphanedPages();
-#if DCHECK_IS_ON()
-  bool contains(void*);
-#endif
-
-  // For orphaned pages, we need to memset with ASan disabled, because
-  // the orphaned pages can still contain poisoned memory or annotated
-  // container but we want to forcibly clear the orphaned pages without
-  // causing ASan errors. asanDisabledMemset must not be used for
-  // non-orphaned pages.
-  static void asanDisabledMemset(Address, char, size_t);
-
- private:
-  void clearMemory(PageMemory*);
-};
-
 }  // namespace blink
 
 #endif