Remove owning_id from EffectNode and replace it by an opaque stable_id

cc/trees/effect_node.cc

Index: cc/trees/effect_node.cc
diff --git a/cc/trees/effect_node.cc b/cc/trees/effect_node.cc
index 464422a2e66b6867a66e3fa34e16456f2a793998..de1b499d7b01793320a86c03a7041ed53f1678a6 100644
--- a/cc/trees/effect_node.cc
+++ b/cc/trees/effect_node.cc
@@ -12,7 +12,7 @@ namespace cc {
 EffectNode::EffectNode()
     : id(EffectTree::kInvalidNodeId),
       parent_id(EffectTree::kInvalidNodeId),
-      owning_layer_id(Layer::INVALID_ID),
+      stable_id(0),
       opacity(1.f),
       screen_space_opacity(1.f),
       blend_mode(SkBlendMode::kSrcOver),
@@ -38,7 +38,7 @@ EffectNode::EffectNode(const EffectNode& other) = default;
 
 bool EffectNode::operator==(const EffectNode& other) const {
   return id == other.id && parent_id == other.parent_id &&
-         owning_layer_id == other.owning_layer_id && opacity == other.opacity &&
+         stable_id == other.stable_id && opacity == other.opacity &&
          screen_space_opacity == other.screen_space_opacity &&
          has_render_surface == other.has_render_surface &&
          has_copy_request == other.has_copy_request &&
@@ -69,7 +69,7 @@ bool EffectNode::operator==(const EffectNode& other) const {
 void EffectNode::AsValueInto(base::trace_event::TracedValue* value) const {
   value->SetInteger("id", id);
   value->SetInteger("parent_id", parent_id);
-  value->SetInteger("owning_layer_id", owning_layer_id);
+  value->SetInteger("stable_id", stable_id);
   value->SetDouble("opacity", opacity);
   value->SetBoolean("has_render_surface", has_render_surface);
   value->SetBoolean("has_copy_request", has_copy_request);