Let clientCacheIsValid count cacheable display item only

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 d54146d98dbdfa01912190385d958460d06395a7..9a0828a8217379159f449d32377de6213188a533 100644
--- a/Source/platform/graphics/paint/DisplayItemList.cpp
+++ b/Source/platform/graphics/paint/DisplayItemList.cpp
@@ -458,13 +458,14 @@ void DisplayItemList::updateValidlyCachedClientsIfNeeded() const
     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);
+        }
     }
 }