Change cc::ElementId to be a uint64_t

cc/layers/layer.cc

Index: cc/layers/layer.cc
diff --git a/cc/layers/layer.cc b/cc/layers/layer.cc
index 2c2bb97f40ba055cdca1d6c2c2c92f79a57e94bd..7e3d9ef11f4471259931dfad312c88f55c83880c 100644
--- a/cc/layers/layer.cc
+++ b/cc/layers/layer.cc
@@ -59,6 +59,7 @@ Layer::Inputs::Inputs(int layer_id)
       main_thread_scrolling_reasons(
           MainThreadScrollingReason::kNotScrollingOnMain),
       is_container_for_fixed_position_layers(false),
+      element_id(kInvalidElementId),
       mutable_properties(MutableProperty::kNone),
       scroll_parent(nullptr),
       clip_parent(nullptr),
@@ -1427,7 +1428,7 @@ void Layer::SetElementId(ElementId id) {
   if (inputs_.element_id == id)
     return;
   TRACE_EVENT1(TRACE_DISABLED_BY_DEFAULT("compositor-worker"),
-               "Layer::SetElementId", "element", id.AsValue().release());
+               "Layer::SetElementId", "element", id);
   if (inputs_.element_id && layer_tree_host()) {
     layer_tree_host_->UnregisterElement(inputs_.element_id,
                                         ElementListType::ACTIVE, this);