[SP] Always paint whole non-custom scrollbars

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 35c10c012e93810feaad47f50e98c6ed72dec2ef..aaaee68b12110bf0f9ece7ad0134b9fe6aaee386 100644
--- a/Source/platform/graphics/paint/DisplayItemList.cpp
+++ b/Source/platform/graphics/paint/DisplayItemList.cpp
@@ -242,11 +242,9 @@ void DisplayItemList::commitNewDisplayItems()
                 updatedList.append(m_currentDisplayItems[currentDisplayItemsIndex].release());
             } else {
                 size_t foundIndex = findOutOfOrderCachedItem(currentDisplayItemsIndex, *newDisplayItem, matchingType, displayItemIndicesByClient);
-                if (foundIndex != kNotFound) {
-                    isSynchronized = (foundIndex == currentDisplayItemsIndex);
-                    updatedList.append(m_currentDisplayItems[foundIndex].release());
-                }
-                // else: do nothing because previously the client generated a empty picture which is not stored in the cache.

[chrishtr, 2015/06/03 21:19:21]

The behavior this comment refers to was removed earlier?

[Xianzhu, 2015/06/03 21:32:56]

Yes. I should have changed the above when I added back dummy display items.

+                ASSERT(foundIndex != kNotFound);
+                isSynchronized = (foundIndex == currentDisplayItemsIndex);
+                updatedList.append(m_currentDisplayItems[foundIndex].release());
             }
         } else {
 #if ENABLE(ASSERT)