Remove owning_id from EffectNode and replace it by an opaque stable_id

third_party/WebKit/Source/platform/graphics/CompositorElementId.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CompositorElementId_h
 #define CompositorElementId_h
 
 #include "cc/trees/element_id.h"
 #include "platform/PlatformExport.h"
 #include "platform/wtf/HashFunctions.h"
 #include "platform/wtf/HashSet.h"
 #include "platform/wtf/HashTraits.h"
 
 namespace blink {
 
 enum class CompositorSubElementId {
   kPrimary,
   kScroll,
   kViewport,
-  kLinkHighlight
+  kLinkHighlight,
+  kScrollbar
 };
 
 using CompositorElementId = cc::ElementId;
 
 CompositorElementId PLATFORM_EXPORT
-CreateCompositorElementId(int dom_node_id, CompositorSubElementId);
+CreateCompositorElementId(int blink_id, CompositorSubElementId);
 
 // Note cc::ElementId has a hash function already implemented via
 // ElementIdHash::operator(). However for consistency's sake we choose to use
 // Blink's hash functions with Blink specific data structures.
 struct CompositorElementIdHash {
   static unsigned GetHash(const CompositorElementId& p) {
     return WTF::HashInts(p.primaryId, p.secondaryId);
   }
   static bool Equal(const CompositorElementId& a,
                     const CompositorElementId& b) {
@@ skipping 13 matching lines @@
   }
 };
 
 using CompositorElementIdSet = HashSet<CompositorElementId,
                                        CompositorElementIdHash,
                                        CompositorElementIdHashTraits>;
 
 }  // namespace blink
 
 #endif  // CompositorElementId_h