Check DisplayItemCient aliveness in cached subsequences

third_party/WebKit/Source/platform/graphics/paint/DisplayItemClient.cpp

Index: third_party/WebKit/Source/platform/graphics/paint/DisplayItemClient.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/paint/DisplayItemClient.cpp b/third_party/WebKit/Source/platform/graphics/paint/DisplayItemClient.cpp
index 7745871824f85076eb9b49e10683437466f794d4..1e196f2ef26e9c762da1f1a54f835f68e0748d55 100644
--- a/third_party/WebKit/Source/platform/graphics/paint/DisplayItemClient.cpp
+++ b/third_party/WebKit/Source/platform/graphics/paint/DisplayItemClient.cpp
@@ -39,6 +39,8 @@ DisplayItemClient::~DisplayItemClient()
         }
     }
     liveDisplayItemClients->remove(this);
+    // In case this object is a subsequence owner.
+    endShouldKeepAliveAllClients(this);
 }
 
 bool DisplayItemClient::isAlive() const
@@ -46,20 +48,20 @@ bool DisplayItemClient::isAlive() const
     return liveDisplayItemClients && liveDisplayItemClients->contains(this);
 }
 
-void DisplayItemClient::beginShouldKeepAlive(const void* paintController) const
+void DisplayItemClient::beginShouldKeepAlive(const void* owner) const
 {
     CHECK(isAlive());
     if (!displayItemClientsShouldKeepAlive)
         displayItemClientsShouldKeepAlive = new HashMap<const void*, HashMap<const DisplayItemClient*, String>>();
-    auto addResult = displayItemClientsShouldKeepAlive->add(paintController, HashMap<const DisplayItemClient*, String>()).storedValue->value.add(this, "");
+    auto addResult = displayItemClientsShouldKeepAlive->add(owner, HashMap<const DisplayItemClient*, String>()).storedValue->value.add(this, "");
     if (addResult.isNewEntry)
         addResult.storedValue->value = debugName();
 }
 
-void DisplayItemClient::endShouldKeepAliveAllClients(const void* paintController)
+void DisplayItemClient::endShouldKeepAliveAllClients(const void* owner)
 {
     if (displayItemClientsShouldKeepAlive)
-        displayItemClientsShouldKeepAlive->remove(paintController);
+        displayItemClientsShouldKeepAlive->remove(owner);
 }
 
 void DisplayItemClient::endShouldKeepAliveAllClients()