Let clientCacheIsValid count cacheable display item only

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/TraceEvent.h"
 #include "platform/graphics/paint/DrawingDisplayItem.h"
@@ skipping 440 matching lines @@
 }
 
 void DisplayItemList::updateValidlyCachedClientsIfNeeded() const
 {
     if (!m_validlyCachedClientsDirty)
         return;
 
     m_validlyCachedClients.clear();
     m_validlyCachedClientsDirty = false;
 
-    DisplayItemClient lastClient = nullptr;
+    DisplayItemClient lastAddedClient = nullptr;
     for (const DisplayItem& displayItem : m_currentDisplayItems) {
-        if (displayItem.client() == lastClient)
+        if (displayItem.client() == lastAddedClient)
             continue;
-        lastClient = displayItem.client();
-        if (!displayItem.skippedCache())
-            m_validlyCachedClients.add(lastClient);
+        if (displayItem.isCacheable()) {
+            lastAddedClient = displayItem.client();
+            m_validlyCachedClients.add(lastAddedClient);
+        }
     }
 }
 
 void DisplayItemList::appendToWebDisplayItemList(WebDisplayItemList* list)
 {
     for (const DisplayItem& item : m_currentDisplayItems)
         item.appendToWebDisplayItemList(list);
 }
 
 void DisplayItemList::commitNewDisplayItemsAndAppendToWebDisplayItemList(WebDisplayItemList* list)
@@ skipping 145 matching lines @@
 
 void DisplayItemList::replay(GraphicsContext& context)
 {
     TRACE_EVENT0("blink,benchmark", "DisplayItemList::replay");
     ASSERT(m_newDisplayItems.isEmpty());
     for (DisplayItem& displayItem : m_currentDisplayItems)
         displayItem.replay(context);
 }
 
 } // namespace blink