Revert of Simple BlinkGC heap compaction.

third_party/WebKit/Source/platform/heap/SparseHeapBitmap.cpp

Index: third_party/WebKit/Source/platform/heap/SparseHeapBitmap.cpp
diff --git a/third_party/WebKit/Source/platform/heap/SparseHeapBitmap.cpp b/third_party/WebKit/Source/platform/heap/SparseHeapBitmap.cpp
deleted file mode 100644
index 6a47decbd3630b70c6aadc991bbe5881b96611d0..0000000000000000000000000000000000000000
--- a/third_party/WebKit/Source/platform/heap/SparseHeapBitmap.cpp
+++ /dev/null
@@ -1,111 +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.
-
-#include "platform/heap/SparseHeapBitmap.h"
-
-#include "wtf/PtrUtil.h"
-
-namespace blink {
-
-// Return the subtree/bitmap that covers the
-// [address, address + size) range.  Null if there is none.
-SparseHeapBitmap* SparseHeapBitmap::hasRange(Address address, size_t size) {
-  DCHECK(!(reinterpret_cast<uintptr_t>(address) & s_pointerAlignmentMask));
-  SparseHeapBitmap* bitmap = this;
-  while (bitmap) {
-    // Interval starts after, |m_right| handles.
-    if (address > bitmap->end()) {
-      bitmap = bitmap->m_right.get();
-      continue;
-    }
-    // Interval starts within, |bitmap| is included in the resulting range.
-    if (address >= bitmap->base())
-      break;
-
-    Address right = address + size - 1;
-    // Interval starts before, but intersects with |bitmap|'s range.
-    if (right >= bitmap->base())
-      break;
-
-    // Interval is before entirely, for |m_left| to handle.
-    bitmap = bitmap->m_left.get();
-  }
-  return bitmap;
-}
-
-bool SparseHeapBitmap::isSet(Address address) {
-  DCHECK(!(reinterpret_cast<uintptr_t>(address) & s_pointerAlignmentMask));
-  SparseHeapBitmap* bitmap = this;
-  while (bitmap) {
-    if (address > bitmap->end()) {
-      bitmap = bitmap->m_right.get();
-      continue;
-    }
-    if (address >= bitmap->base()) {
-      if (bitmap->m_bitmap) {
-        return bitmap->m_bitmap->test((address - bitmap->base()) >>
-                                      s_pointerAlignmentInBits);
-      }
-      DCHECK(address == bitmap->base());
-      DCHECK_EQ(bitmap->size(), 1u);
-      return true;
-    }
-    bitmap = bitmap->m_left.get();
-  }
-  return false;
-}
-
-void SparseHeapBitmap::add(Address address) {
-  DCHECK(!(reinterpret_cast<uintptr_t>(address) & s_pointerAlignmentMask));
-  // |address| is beyond the maximum that this SparseHeapBitmap node can
-  // encompass.
-  if (address >= maxEnd()) {
-    if (!m_right) {
-      m_right = SparseHeapBitmap::create(address);
-      return;
-    }
-    m_right->add(address);
-    return;
-  }
-  // Same on the other side.
-  if (address < minStart()) {
-    if (!m_left) {
-      m_left = SparseHeapBitmap::create(address);
-      return;
-    }
-    m_left->add(address);
-    return;
-  }
-  if (address == base())
-    return;
-  // |address| can be encompassed by |this| by expanding its size.
-  if (address > base()) {
-    if (!m_bitmap)
-      createBitmap();
-    m_bitmap->set((address - base()) >> s_pointerAlignmentInBits);
-    return;
-  }
-  // Use |address| as the new base for this interval.
-  Address oldBase = swapBase(address);
-  createBitmap();
-  m_bitmap->set((oldBase - address) >> s_pointerAlignmentInBits);
-}
-
-void SparseHeapBitmap::createBitmap() {
-  DCHECK(!m_bitmap && size() == 1);
-  m_bitmap = WTF::makeUnique<std::bitset<s_bitmapChunkSize>>();
-  m_size = s_bitmapChunkRange;
-  m_bitmap->set(0);
-}
-
-size_t SparseHeapBitmap::intervalCount() const {
-  size_t count = 1;
-  if (m_left)
-    count += m_left->intervalCount();
-  if (m_right)
-    count += m_right->intervalCount();
-  return count;
-}
-
-}  // namespace blink