[SPv1] Always set a CompositorElementId on main graphics layers; use PaintLayer id.

third_party/WebKit/Source/core/animation/CompositorAnimations.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 428 matching lines @@
   DCHECK(compositor_player);
   compositor_player->PauseAnimation(id, pause_time);
 }
 
 void CompositorAnimations::AttachCompositedLayers(Element& element,
                                                   const Animation& animation) {
   if (!animation.CompositorPlayer())
     return;
 
   if (!element.GetLayoutObject() ||
-      !element.GetLayoutObject()->IsBoxModelObject())
+      !element.GetLayoutObject()->IsBoxModelObject() ||
+      !element.GetLayoutObject()->HasLayer())
     return;
 
+  PaintLayer* layer =
+      ToLayoutBoxModelObject(element.GetLayoutObject())->Layer();
+
   // Composited animations do not depend on a composited layer mapping for SPv2.
   if (!RuntimeEnabledFeatures::slimmingPaintV2Enabled()) {
-    PaintLayer* layer =
-        ToLayoutBoxModelObject(element.GetLayoutObject())->Layer();
-
-    if (!layer || !layer->IsAllowedToQueryCompositingState() ||
+    if (!layer->IsAllowedToQueryCompositingState() ||
         !layer->GetCompositedLayerMapping() ||
         !layer->GetCompositedLayerMapping()->MainGraphicsLayer())
       return;
 
     if (!layer->GetCompositedLayerMapping()
              ->MainGraphicsLayer()
              ->PlatformLayer())
       return;
   }
 
   CompositorAnimationPlayer* compositor_player = animation.CompositorPlayer();
-  compositor_player->AttachElement(CompositorElementIdFromDOMNodeId(
-      DOMNodeIds::IdForNode(&element), CompositorElementIdNamespace::kPrimary));
+  compositor_player->AttachElement(CompositorElementIdFromPaintLayerId(
+      layer->UniqueId(), CompositorElementIdNamespace::kPrimary));
 }
 
 bool CompositorAnimations::ConvertTimingForCompositor(
     const Timing& timing,
     double time_offset,
     CompositorTiming& out,
     double animation_playback_rate) {
   timing.AssertValid();
 
   // FIXME: Compositor does not know anything about endDelay.
@@ skipping 166 matching lines @@
     animation->SetTimeOffset(compositor_timing.scaled_time_offset);
     animation->SetDirection(compositor_timing.direction);
     animation->SetPlaybackRate(compositor_timing.playback_rate);
     animation->SetFillMode(compositor_timing.fill_mode);
     animations.push_back(std::move(animation));
   }
   DCHECK(!animations.IsEmpty());
 }
 
 }  // namespace blink