Change cc::ElementId to be a uint64_t

cc/layers/layer_impl.cc

Index: cc/layers/layer_impl.cc
diff --git a/cc/layers/layer_impl.cc b/cc/layers/layer_impl.cc
index 3006bd5ad50e3f9d39bc95add9f8f63b18d769da..db4ae4a928ac62108db1c768add2679d9c4813bc 100644
--- a/cc/layers/layer_impl.cc
+++ b/cc/layers/layer_impl.cc
@@ -75,6 +75,7 @@ LayerImpl::LayerImpl(LayerTreeImpl* tree_impl, int id)
       clip_tree_index_(ClipTree::kInvalidNodeId),
       scroll_tree_index_(ScrollTree::kInvalidNodeId),
       current_draw_mode_(DRAW_MODE_NONE),
+      element_id_(kInvalidElementId),
       mutable_properties_(MutableProperty::kNone),
       debug_info_(nullptr),
       has_will_change_transform_hint_(false),
@@ -630,8 +631,7 @@ void LayerImpl::SetElementId(ElementId element_id) {
     return;
 
   TRACE_EVENT1(TRACE_DISABLED_BY_DEFAULT("compositor-worker"),
-               "LayerImpl::SetElementId", "element",
-               element_id.AsValue().release());
+               "LayerImpl::SetElementId", "element", element_id);
 
   layer_tree_impl_->RemoveFromElementMap(this);
   element_id_ = element_id;
@@ -798,7 +798,7 @@ void LayerImpl::AsValueInto(base::trace_event::TracedValue* state) const {
                     base::saturated_cast<int>(GPUMemoryUsageInBytes()));
 
   if (element_id_)
-    element_id_.AddToTracedValue(state);
+    state->SetInteger("element_id", element_id_);
 
   if (mutable_properties_ != MutableProperty::kNone)
     state->SetInteger("mutable_properties", mutable_properties_);