Use element id's for animations

cc/blink/web_layer_impl.cc

Index: cc/blink/web_layer_impl.cc
diff --git a/cc/blink/web_layer_impl.cc b/cc/blink/web_layer_impl.cc
index abb6e501137ba8a88c69e4d0e0657416f571ed4a..e81c093ea580b38a41a01fe5657e72cc8aa92019 100644
--- a/cc/blink/web_layer_impl.cc
+++ b/cc/blink/web_layer_impl.cc
@@ -14,6 +14,7 @@
 #include "base/strings/string_util.h"
 #include "base/threading/thread_checker.h"
 #include "base/trace_event/trace_event_impl.h"
+#include "cc/animation/element_id.h"
 #include "cc/base/region.h"
 #include "cc/base/switches.h"
 #include "cc/blink/web_blend_mode.h"
@@ -379,11 +380,11 @@ cc::Layer* WebLayerImpl::ccLayer() {
   return layer_.get();
 }
 
-void WebLayerImpl::setElementId(uint64_t id) {
+void WebLayerImpl::setElementId(const cc::ElementId& id) {
   layer_->SetElementId(id);
 }
 
-uint64_t WebLayerImpl::elementId() const {
+cc::ElementId WebLayerImpl::elementId() const {
   return layer_->element_id();
 }