Reland of Check DisplayItemCient aliveness in cached subsequences

third_party/WebKit/Source/core/paint/PaintLayer.cpp

Index: third_party/WebKit/Source/core/paint/PaintLayer.cpp
diff --git a/third_party/WebKit/Source/core/paint/PaintLayer.cpp b/third_party/WebKit/Source/core/paint/PaintLayer.cpp
index 63490d93975d90e25af178863d1094bd29dfb420..02920656822221ef7998e290161f85cbf559871f 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayer.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintLayer.cpp
@@ -2888,8 +2888,10 @@
                 break;
             container = owner->enclosingLayer();
         }
+
         if (container->m_needsRepaint)
             break;
+
         container->setNeedsRepaintInternal();
         layer = container;
     }
@@ -2909,6 +2911,15 @@
     return nullptr;
 }
 
+void PaintLayer::endShouldKeepAliveAllClientsRecursive()
+{
+    for (PaintLayer* child = firstChild(); child; child = child->nextSibling())
+        child->endShouldKeepAliveAllClientsRecursive();
+#if CHECK_DISPLAY_ITEM_CLIENT_ALIVENESS
+    DisplayItemClient::endShouldKeepAliveAllClients(this);
+#endif
+}
+
 DisableCompositingQueryAsserts::DisableCompositingQueryAsserts()
     : m_disabler(gCompositingQueryMode, CompositingQueriesAreAllowed) { }