Revert of Simple BlinkGC heap compaction.

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

Index: third_party/WebKit/Source/platform/heap/HeapCompact.h
diff --git a/third_party/WebKit/Source/platform/heap/HeapCompact.h b/third_party/WebKit/Source/platform/heap/HeapCompact.h
deleted file mode 100644
index 8565eb9065805e4609d51ee87f0615295b4ed40d..0000000000000000000000000000000000000000
--- a/third_party/WebKit/Source/platform/heap/HeapCompact.h
+++ /dev/null
@@ -1,207 +0,0 @@
-// Copyright 2016 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 HeapCompact_h
-#define HeapCompact_h
-
-#include "platform/PlatformExport.h"
-#include "platform/heap/BlinkGC.h"
-#include "wtf/DataLog.h"
-#include "wtf/PtrUtil.h"
-#include "wtf/ThreadingPrimitives.h"
-#include "wtf/Vector.h"
-
-#include <bitset>
-#include <utility>
-
-// Compaction-specific debug switches:
-
-// Set to 0 to prevent compaction GCs, disabling the heap compaction feature.
-#define ENABLE_HEAP_COMPACTION 1
-
-// Emit debug info during compaction.
-#define DEBUG_HEAP_COMPACTION 0
-
-// Emit stats on freelist occupancy.
-// 0 - disabled, 1 - minimal, 2 - verbose.
-#define DEBUG_HEAP_FREELIST 0
-
-// Log the amount of time spent compacting.
-#define DEBUG_LOG_HEAP_COMPACTION_RUNNING_TIME 0
-
-// Compact during all idle + precise GCs; for debugging.
-#define STRESS_TEST_HEAP_COMPACTION 0
-
-namespace blink {
-
-class NormalPageArena;
-class BasePage;
-class ThreadState;
-
-class PLATFORM_EXPORT HeapCompact final {
- public:
-  static std::unique_ptr<HeapCompact> create() {
-    return WTF::wrapUnique(new HeapCompact);
-  }
-
-  ~HeapCompact();
-
-  // Determine if a GC for the given type and reason should also perform
-  // additional heap compaction.
-  //
-  bool shouldCompact(ThreadState*, BlinkGC::GCType, BlinkGC::GCReason);
-
-  // Compaction should be performed as part of the ongoing GC, initialize
-  // the heap compaction pass. Returns the appropriate visitor type to
-  // use when running the marking phase.
-  BlinkGC::GCType initialize(ThreadState*);
-
-  // Returns true if the ongoing GC will perform compaction.
-  bool isCompacting() const { return m_doCompact; }
-
-  // Returns true if the ongoing GC will perform compaction for the given
-  // heap arena.
-  bool isCompactingArena(int arenaIndex) const {
-    return m_doCompact && (m_compactableArenas & (0x1u << arenaIndex));
-  }
-
-  // Returns |true| if the ongoing GC may compact the given arena/sub-heap.
-  static bool isCompactableArena(int arenaIndex) {
-    return arenaIndex >= BlinkGC::Vector1ArenaIndex &&
-           arenaIndex <= BlinkGC::HashTableArenaIndex;
-  }
-
-  // See |Heap::registerMovingObjectReference()| documentation.
-  void registerMovingObjectReference(MovableReference* slot);
-
-  // See |Heap::registerMovingObjectCallback()| documentation.
-  void registerMovingObjectCallback(MovableReference,
-                                    MovingObjectCallback,
-                                    void* callbackData);
-
-  // Thread signalling that a compaction pass is starting or has
-  // completed.
-  //
-  // A thread participating in a heap GC will wait on the completion
-  // of compaction across all threads. No thread can be allowed to
-  // potentially access another thread's heap arenas while they're
-  // still being compacted.
-  void startThreadCompaction();
-  void finishThreadCompaction();
-
-  // Perform any relocation post-processing after having completed compacting
-  // the given arena. The number of pages that were freed together with the
-  // total size (in bytes) of freed heap storage, are passed in as arguments.
-  void finishedArenaCompaction(NormalPageArena*,
-                               size_t freedPages,
-                               size_t freedSize);
-
-  // Register the heap page as containing live objects that will all be
-  // compacted. Registration happens as part of making the arenas ready
-  // for a GC.
-  void addCompactingPage(BasePage*);
-
-  // Notify heap compaction that object at |from| has been relocated to.. |to|.
-  // (Called by the sweep compaction pass.)
-  void relocate(Address from, Address to);
-
-  // For unit testing only: arrange for a compaction GC to be triggered
-  // next time a non-conservative GC is run. Sets the compact-next flag
-  // to the new value, returning old.
-  static bool scheduleCompactionGCForTesting(bool);
-
- private:
-  class MovableObjectFixups;
-
-  HeapCompact();
-
-  // Sample the amount of fragmentation and heap memory currently residing
-  // on the freelists of the arenas we're able to compact. The computed
-  // numbers will be subsequently used to determine if a heap compaction
-  // is on order (shouldCompact().)
-  void updateHeapResidency(ThreadState*);
-
-  // Parameters controlling when compaction should be done:
-
-  // Number of GCs that must have passed since last compaction GC.
-  static const int kGCCountSinceLastCompactionThreshold = 10;
-
-  // Freelist size threshold that must be exceeded before compaction
-  // should be considered.
-  static const size_t kFreeListSizeThreshold = 512 * 1024;
-
-  MovableObjectFixups& fixups();
-
-  std::unique_ptr<MovableObjectFixups> m_fixups;
-
-  // Set to |true| when a compacting sweep will go ahead.
-  bool m_doCompact;
-  size_t m_gcCountSinceLastCompaction;
-
-  // Lock protecting finishedThreadCompaction() signalling.
-  Mutex m_mutex;
-
-  // All threads performing a GC must synchronize on completion
-  // of all heap compactions. Not doing so risks one thread resuming
-  // the mutator, which could perform cross-thread access to a heap
-  // that's still in the process of being compacted.
-  ThreadCondition m_finished;
-
-  // Number of heap threads participating in the compaction.
-  int m_threadCount;
-
-  // Last reported freelist size, across all compactable arenas.
-  size_t m_freeListSize;
-
-  // If compacting, i'th heap arena will be compacted
-  // if corresponding bit is set. Indexes are in
-  // the range of BlinkGC::ArenaIndices.
-  unsigned m_compactableArenas;
-
-  // Stats, number of (complete) pages freed/decommitted +
-  // bytes freed (which will include partial pages.)
-  size_t m_freedPages;
-  size_t m_freedSize;
-
-#if DEBUG_LOG_HEAP_COMPACTION_RUNNING_TIME
-  double m_startCompactionTimeMS;
-#endif
-
-  static bool s_forceCompactionGC;
-};
-
-}  // namespace blink
-
-// Logging macros activated by debug switches.
-
-#define LOG_HEAP_COMPACTION_INTERNAL(msg, ...) dataLogF(msg, ##__VA_ARGS__)
-
-#if DEBUG_HEAP_COMPACTION
-#define LOG_HEAP_COMPACTION(msg, ...) \
-  LOG_HEAP_COMPACTION_INTERNAL(msg, ##__VA_ARGS__)
-#else
-#define LOG_HEAP_COMPACTION(msg, ...) \
-  do {                                \
-  } while (0)
-#endif
-
-#if DEBUG_HEAP_FREELIST
-#define LOG_HEAP_FREELIST(msg, ...) \
-  LOG_HEAP_COMPACTION_INTERNAL(msg, ##__VA_ARGS__)
-#else
-#define LOG_HEAP_FREELIST(msg, ...) \
-  do {                              \
-  } while (0)
-#endif
-
-#if DEBUG_HEAP_FREELIST == 2
-#define LOG_HEAP_FREELIST_VERBOSE(msg, ...) \
-  LOG_HEAP_COMPACTION_INTERNAL(msg, ##__VA_ARGS__)
-#else
-#define LOG_HEAP_FREELIST_VERBOSE(msg, ...) \
-  do {                                      \
-  } while (0)
-#endif
-
-#endif  // HeapCompact_h