Add tracing for ContentLayerDelegate paintContents and DisplayItemList commit.

Source/platform/graphics/paint/DisplayItemList.cpp

 // 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"
 #include "platform/TraceEvent.h"
@@ skipping 48 matching lines @@
 #endif
     m_newDisplayItems.removeLast();
 }
 
 void DisplayItemList::add(WTF::PassOwnPtr<DisplayItem> displayItem)
 {
     ASSERT(RuntimeEnabledFeatures::slimmingPaintEnabled());
     ASSERT(!m_constructionDisabled);
     ASSERT(!skippingCache() || !displayItem->isCached());
 
+    if (DisplayItem::isCachedType(displayItem->type()))
+        ++m_numCachedItems;
+
 #if ENABLE(ASSERT)
     // Verify noop begin/end pairs have been removed.
     if (!m_newDisplayItems.isEmpty() && m_newDisplayItems.last().isBegin() && !m_newDisplayItems.last().drawsContent())
         ASSERT(!displayItem->isEndAndPairedWith(m_newDisplayItems.last().type()));
 #endif
 
     if (!m_scopeStack.isEmpty())
         displayItem->setScope(m_scopeStack.last().id, m_scopeStack.last().client);
 
 #if ENABLE(ASSERT)
@@ skipping 129 matching lines @@
 // - FIXME: Re-enable SubtreeCachedDisplayItem:
 //   For SubtreeCachedDisplayItem, copy the cached display items between the
 //   corresponding BeginSubtreeDisplayItem and EndSubtreeDisplayItem (incl.);
 // - Otherwise, copy the new display item.
 //
 // The algorithm is O(|m_currentDisplayItems| + |m_newDisplayItems|).
 // Coefficients are related to the ratio of out-of-order [Subtree]CachedDisplayItems
 // and the average number of (Drawing|BeginSubtree)DisplayItems per client.
 void DisplayItemList::commitNewDisplayItems()
 {
-    TRACE_EVENT0("blink,benchmark", "DisplayItemList::commitNewDisplayItems");
+    TRACE_EVENT2("blink,benchmark", "DisplayItemList::commitNewDisplayItems", "current_display_list_size", (int)m_currentDisplayItems.size(),
+        "num_non_cached_new_items", (int)m_newDisplayItems.size() - m_numCachedItems);
 
     // These data structures are used during painting only.
     m_clientScopeIdMap.clear();
     ASSERT(m_scopeStack.isEmpty());
     m_scopeStack.clear();
     ASSERT(!skippingCache());
 #if ENABLE(ASSERT)
     m_newDisplayItemIndicesByClient.clear();
 #endif
 
     if (m_currentDisplayItems.isEmpty()) {
 #if ENABLE(ASSERT)
         for (auto& item : m_newDisplayItems) {
             ASSERT(!DisplayItem::isCachedType(item.type())
                 && !DisplayItem::isSubtreeCachedType(item.type()));
         }
 #endif
         m_currentDisplayItems.swap(m_newDisplayItems);
         m_validlyCachedClientsDirty = true;
+        m_numCachedItems = 0;
         return;
     }
 
     updateValidlyCachedClientsIfNeeded();
 
     // Stores indices to valid DrawingDisplayItems in m_currentDisplayItems that have not been matched
     // by CachedDisplayItems during synchronized matching. The indexed items will be matched
     // by later out-of-order CachedDisplayItems in m_newDisplayItems. This ensures that when
     // out-of-order CachedDisplayItems occur, we only traverse at most once over m_currentDisplayItems
     // looking for potential matches. Thus we can ensure that the algorithm runs in linear time.
@@ skipping 65 matching lines @@
 
 #if ENABLE(ASSERT)
     if (RuntimeEnabledFeatures::slimmingPaintUnderInvalidationCheckingEnabled())
         checkNoRemainingCachedDisplayItems();
 #endif // ENABLE(ASSERT)
 
     m_newDisplayItems.clear();
     m_validlyCachedClientsDirty = true;
     m_currentDisplayItems.clear();
     m_currentDisplayItems.swap(updatedList);
+    m_numCachedItems = 0;
 }
 
 void DisplayItemList::updateValidlyCachedClientsIfNeeded() const
 {
     if (!m_validlyCachedClientsDirty)
         return;
 
     m_validlyCachedClients.clear();
     m_validlyCachedClientsDirty = false;
 
@@ skipping 157 matching lines @@
 
 void DisplayItemList::replay(GraphicsContext& context) const
 {
     TRACE_EVENT0("blink,benchmark", "DisplayItemList::replay");
     ASSERT(m_newDisplayItems.isEmpty());
     for (auto& displayItem : m_currentDisplayItems)
         displayItem.replay(context);
 }
 
 } // namespace blink