Revert of Use element id's for animations

cc/layers/layer.cc

Index: cc/layers/layer.cc
diff --git a/cc/layers/layer.cc b/cc/layers/layer.cc
index a2bd6345629fe98ff7348e2252bb91aca97ba06d..284bb1ebe95caeb792cf1219d04b263d092e2e6e 100644
--- a/cc/layers/layer.cc
+++ b/cc/layers/layer.cc
@@ -15,7 +15,6 @@
 #include "base/single_thread_task_runner.h"
 #include "base/time/time.h"
 #include "base/trace_event/trace_event.h"
-#include "cc/animation/animation_host.h"
 #include "cc/animation/mutable_properties.h"
 #include "cc/base/simple_enclosed_region.h"
 #include "cc/debug/frame_viewer_instrumentation.h"
@@ -59,6 +58,7 @@
       clip_tree_index_(-1),
       scroll_tree_index_(-1),
       property_tree_sequence_number_(-1),
+      element_id_(0),
       mutable_properties_(MutableProperty::kNone),
       main_thread_scrolling_reasons_(
           MainThreadScrollingReason::kNotScrollingOnMain),
@@ -122,20 +122,10 @@
     layer_tree_host_->property_trees()->RemoveIdFromIdToIndexMaps(id());
     layer_tree_host_->property_trees()->needs_rebuild = true;
     layer_tree_host_->UnregisterLayer(this);
-    if (element_id_) {
-      layer_tree_host_->animation_host()->UnregisterElement(
-          element_id_, ElementListType::ACTIVE);
-      layer_tree_host_->RemoveFromElementMap(this);
-    }
   }
   if (host) {
     host->property_trees()->needs_rebuild = true;
     host->RegisterLayer(this);
-    if (element_id_) {
-      host->AddToElementMap(this);
-      host->animation_host()->RegisterElement(element_id_,
-                                              ElementListType::ACTIVE);
-    }
   }
 
   layer_tree_host_ = host;
@@ -1802,26 +1792,13 @@
   benchmark->RunOnLayer(this);
 }
 
-void Layer::SetElementId(ElementId id) {
+void Layer::SetElementId(uint64_t id) {
   DCHECK(IsPropertyChangeAllowed());
   if (element_id_ == id)
     return;
   TRACE_EVENT1(TRACE_DISABLED_BY_DEFAULT("compositor-worker"),
-               "Layer::SetElementId", "element", id.AsValue().release());
-  if (element_id_ && layer_tree_host()) {
-    layer_tree_host()->animation_host()->UnregisterElement(
-        element_id_, ElementListType::ACTIVE);
-    layer_tree_host()->RemoveFromElementMap(this);
-  }
-
+               "Layer::SetElementId", "id", id);
   element_id_ = id;
-
-  if (element_id_ && layer_tree_host()) {
-    layer_tree_host()->animation_host()->RegisterElement(
-        element_id_, ElementListType::ACTIVE);
-    layer_tree_host()->AddToElementMap(this);
-  }
-
   SetNeedsCommit();
 }