[Slimming Paint] Blink-side contiguous allocation of display items.

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
index ecff614061bf8af43a29f071b3b0343024db4298..236cbecca2c646ede78ad97478732fcfd1db4bc6 100644
--- a/Source/platform/graphics/paint/DisplayItemList.cpp
+++ b/Source/platform/graphics/paint/DisplayItemList.cpp
@@ -32,21 +32,21 @@ const DisplayItems& DisplayItemList::displayItems() const
     return m_currentDisplayItems;
 }
 
-void DisplayItemList::add(WTF::PassOwnPtr<DisplayItem> displayItem)
+void DisplayItemList::add(DisplayItem& displayItem)
 {
     ASSERT(RuntimeEnabledFeatures::slimmingPaintEnabled());
     ASSERT(!m_constructionDisabled);
-    ASSERT(!skippingCache() || !displayItem->isCached());
+    ASSERT(!skippingCache() || !displayItem.isCached());
 
-    if (displayItem->isEnd()) {
+    if (displayItem.isEnd()) {
         ASSERT(!m_newDisplayItems.isEmpty());
         if (m_newDisplayItems.last().isBegin() && !m_newDisplayItems.last().drawsContent()) {
-            ASSERT(displayItem->isEndAndPairedWith(m_newDisplayItems.last().type()));
+            ASSERT(displayItem.isEndAndPairedWith(m_newDisplayItems.last().type()));
             // Remove the beginning display item of this empty pair.
             m_newDisplayItems.removeLast();
 #if ENABLE(ASSERT)
             // Also remove the index pointing to the removed display item.
-            DisplayItemIndicesByClientMap::iterator it = m_newDisplayItemIndicesByClient.find(displayItem->client());
+            DisplayItemIndicesByClientMap::iterator it = m_newDisplayItemIndicesByClient.find(displayItem.client());
             if (it != m_newDisplayItemIndicesByClient.end()) {
                 Vector<size_t>& indices = it->value;
                 if (!indices.isEmpty() && indices.last() == m_newDisplayItems.size())
@@ -58,26 +58,26 @@ void DisplayItemList::add(WTF::PassOwnPtr<DisplayItem> displayItem)
     }
 
     if (!m_scopeStack.isEmpty())
-        displayItem->setScope(m_scopeStack.last().id, m_scopeStack.last().client);
+        displayItem.setScope(m_scopeStack.last().id, m_scopeStack.last().client);
 
 #if ENABLE(ASSERT)
-    size_t index = findMatchingItemFromIndex(displayItem->id(), displayItem->type(), m_newDisplayItemIndicesByClient, m_newDisplayItems);
+    size_t index = findMatchingItemFromIndex(displayItem.id(), displayItem.type(), m_newDisplayItemIndicesByClient, m_newDisplayItems);
     if (index != kNotFound) {
 #ifndef NDEBUG
         showDebugData();
         WTFLogAlways("DisplayItem %s has duplicated id with previous %s (index=%d)\n",
-            displayItem->asDebugString().utf8().data(), m_newDisplayItems[index].asDebugString().utf8().data(), static_cast<int>(index));
+            displayItem.asDebugString().utf8().data(), m_newDisplayItems[index].asDebugString().utf8().data(), static_cast<int>(index));
 #endif
         ASSERT_NOT_REACHED();
     }
-    addItemToIndex(displayItem->client(), displayItem->type(), m_newDisplayItems.size(), m_newDisplayItemIndicesByClient);
+    addItemToIndex(displayItem.client(), displayItem.type(), m_newDisplayItems.size(), m_newDisplayItemIndicesByClient);
 #endif // ENABLE(ASSERT)
 
-    ASSERT(!displayItem->skippedCache()); // Only DisplayItemList can set the flag.
+    ASSERT(!displayItem.skippedCache()); // Only DisplayItemList can set the flag.
     if (skippingCache())
-        displayItem->setSkippedCache();
+        displayItem.setSkippedCache();
 
-    m_newDisplayItems.append(displayItem);
+    displayItem.appendByMoving(m_newDisplayItems);
 }
 
 void DisplayItemList::beginScope(DisplayItemClient client)