Revert of Move ViewDisplayList to GraphicsLayer

Source/platform/graphics/paint/DisplayItemList.cpp

Index: Source/platform/graphics/paint/DisplayItemList.cpp
diff --git a/Source/platform/graphics/paint/DisplayItemList.cpp b/Source/platform/graphics/paint/DisplayItemList.cpp
deleted file mode 100644
index 3e9268525a9cec15b06dd15dd1edba975627d3d3..0000000000000000000000000000000000000000
--- a/Source/platform/graphics/paint/DisplayItemList.cpp
+++ /dev/null
@@ -1,136 +0,0 @@
-// Copyright 2014 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 "config.h"
-#include "platform/graphics/paint/DisplayItemList.h"
-
-#include "platform/NotImplemented.h"
-#include "platform/RuntimeEnabledFeatures.h"
-#ifndef NDEBUG
-#include "platform/graphics/paint/DisplayItem.h"
-#include "wtf/text/StringBuilder.h"
-#endif
-
-namespace blink {
-
-const PaintList& DisplayItemList::paintList()
-{
-    ASSERT(RuntimeEnabledFeatures::slimmingPaintEnabled());
-
-    updatePaintList();
-    return m_paintList;
-}
-
-void DisplayItemList::add(WTF::PassOwnPtr<DisplayItem> displayItem)
-{
-    ASSERT(RuntimeEnabledFeatures::slimmingPaintEnabled());
-    m_newPaints.append(displayItem);
-}
-
-void DisplayItemList::invalidate(DisplayItemClient renderer)
-{
-    ASSERT(RuntimeEnabledFeatures::slimmingPaintEnabled());
-    m_invalidated.add(renderer);
-}
-
-PaintList::iterator DisplayItemList::findDisplayItem(PaintList::iterator begin, const DisplayItem& displayItem)
-{
-    PaintList::iterator end = m_paintList.end();
-    if (displayItem.client() && !m_paintListRenderers.contains(displayItem.client()))
-        return end;
-
-    for (PaintList::iterator it = begin; it != end; ++it) {
-        DisplayItem& existing = **it;
-        if (existing.idsEqual(displayItem))
-            return it;
-    }
-
-    // FIXME: Properly handle clips.
-    ASSERT(!displayItem.client());
-    return end;
-}
-
-bool DisplayItemList::wasInvalidated(const DisplayItem& displayItem) const
-{
-    // FIXME: Use a bit on DisplayItemClient instead of tracking m_invalidated.
-    return displayItem.client() && m_invalidated.contains(displayItem.client());
-}
-
-static void appendDisplayItem(PaintList& list, HashSet<DisplayItemClient>& renderers, WTF::PassOwnPtr<DisplayItem> displayItem)
-{
-    if (DisplayItemClient renderer = displayItem->client())
-        renderers.add(renderer);
-    list.append(displayItem);
-}
-
-// Update the existing paintList by removing invalidated entries, updating
-// repainted ones, and appending new items.
-//
-// The algorithm is O(|existing paint list| + |newly painted list|): by using
-// the ordering implied by the existing paint list, extra treewalks are avoided.
-void DisplayItemList::updatePaintList()
-{
-    PaintList updatedList;
-    HashSet<DisplayItemClient> updatedRenderers;
-
-    if (int maxCapacity = m_newPaints.size() + std::max(0, (int)m_paintList.size() - (int)m_invalidated.size()))
-        updatedList.reserveCapacity(maxCapacity);
-
-    PaintList::iterator paintListIt = m_paintList.begin();
-    PaintList::iterator paintListEnd = m_paintList.end();
-
-    for (OwnPtr<DisplayItem>& newDisplayItem : m_newPaints) {
-        if (!wasInvalidated(*newDisplayItem)) {
-            PaintList::iterator repaintIt = findDisplayItem(paintListIt, *newDisplayItem);
-            if (repaintIt != paintListEnd) {
-                // Copy all of the existing items over until we hit the repaint.
-                for (; paintListIt != repaintIt; ++paintListIt) {
-                    if (!wasInvalidated(**paintListIt))
-                        appendDisplayItem(updatedList, updatedRenderers, paintListIt->release());
-                }
-                paintListIt++;
-            }
-        }
-        // Copy over the new item.
-        appendDisplayItem(updatedList, updatedRenderers, newDisplayItem.release());
-    }
-
-    // Copy over any remaining items that were not invalidated.
-    for (; paintListIt != paintListEnd; ++paintListIt) {
-        if (!wasInvalidated(**paintListIt))
-            appendDisplayItem(updatedList, updatedRenderers, paintListIt->release());
-    }
-
-    m_invalidated.clear();
-    m_newPaints.clear();
-    m_paintList.clear();
-    m_paintList.swap(updatedList);
-    m_paintListRenderers.clear();
-    m_paintListRenderers.swap(updatedRenderers);
-}
-
-#ifndef NDEBUG
-
-static WTF::String paintListAsDebugString(const PaintList& list)
-{
-    StringBuilder stringBuilder;
-    bool isFirst = true;
-    for (auto& displayItem : list) {
-        if (!isFirst)
-            stringBuilder.append(", ");
-        isFirst = false;
-        stringBuilder.append(displayItem->asDebugString());
-    }
-    return stringBuilder.toString();
-}
-
-void DisplayItemList::showDebugData() const
-{
-    fprintf(stderr, "paint list: [%s]\n", paintListAsDebugString(m_paintList).utf8().data());
-    fprintf(stderr, "new paints: [%s]\n", paintListAsDebugString(m_newPaints).utf8().data());
-}
-
-#endif
-
-} // namespace blink