Use element id's for animations

third_party/WebKit/Source/core/page/scrolling/ScrollState.cpp

Index: third_party/WebKit/Source/core/page/scrolling/ScrollState.cpp
diff --git a/third_party/WebKit/Source/core/page/scrolling/ScrollState.cpp b/third_party/WebKit/Source/core/page/scrolling/ScrollState.cpp
index e8caadad48460e23328ed495ca5682b3e4b073f5..03a39b5042171471be6a733bd8ae6add63523cf1 100644
--- a/third_party/WebKit/Source/core/page/scrolling/ScrollState.cpp
+++ b/third_party/WebKit/Source/core/page/scrolling/ScrollState.cpp
@@ -7,6 +7,7 @@
 #include "core/dom/DOMNodeIds.h"
 #include "core/dom/Element.h"
 #include "core/dom/ExceptionCode.h"
+#include "platform/graphics/CompositorElementId.h"
 
 namespace blink {
 
@@ -92,7 +93,7 @@ void ScrollState::consumeDeltaNative(double x, double y)
 
 Element* ScrollState::currentNativeScrollingElement() const
 {
-    uint64_t elementId = m_data->current_native_scrolling_element();
+    uint64_t elementId = m_data->current_native_scrolling_element().primaryId;
     if (elementId == 0)
         return nullptr;
     return elementForId(elementId);
@@ -100,12 +101,12 @@ Element* ScrollState::currentNativeScrollingElement() const
 
 void ScrollState::setCurrentNativeScrollingElement(Element* element)
 {
-    m_data->set_current_native_scrolling_element(DOMNodeIds::idForNode(element));
+    m_data->set_current_native_scrolling_element(createCompositorElementId(DOMNodeIds::idForNode(element), CompositorSubElementId::Scroll));
 }
 
 void ScrollState::setCurrentNativeScrollingElementById(int elementId)
 {
-    m_data->set_current_native_scrolling_element(elementId);
+    m_data->set_current_native_scrolling_element(createCompositorElementId(elementId, CompositorSubElementId::Scroll));
 }
 
 } // namespace blink