CC Animation: Unify ElementId in Blink Compositor Worker.

cc/blink/web_layer_impl.h

 // Copyright 2014 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 CC_BLINK_WEB_LAYER_IMPL_H_
 #define CC_BLINK_WEB_LAYER_IMPL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <memory>
 #include <string>
 #include <utility>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "cc/blink/cc_blink_export.h"
 #include "cc/layers/layer_client.h"
+#include "cc/trees/element_id.h"
 #include "third_party/WebKit/public/platform/WebColor.h"
 #include "third_party/WebKit/public/platform/WebDoublePoint.h"
 #include "third_party/WebKit/public/platform/WebFloatPoint.h"
 #include "third_party/WebKit/public/platform/WebLayer.h"
 #include "third_party/WebKit/public/platform/WebPoint.h"
 #include "third_party/WebKit/public/platform/WebRect.h"
 #include "third_party/WebKit/public/platform/WebSize.h"
 #include "third_party/WebKit/public/platform/WebString.h"
 #include "third_party/WebKit/public/platform/WebVector.h"
 #include "third_party/skia/include/core/SkMatrix44.h"
@@ skipping 90 matching lines @@
   blink::WebVector<blink::WebRect> touchEventHandlerRegion() const override;
   void setIsContainerForFixedPositionLayers(bool is_container) override;
   bool isContainerForFixedPositionLayers() const override;
   void setPositionConstraint(
       const blink::WebLayerPositionConstraint& constraint) override;
   blink::WebLayerPositionConstraint positionConstraint() const override;
   void setScrollClient(blink::WebLayerScrollClient* client) override;
   void setLayerClient(cc::LayerClient* client) override;
   const cc::Layer* ccLayer() const override;
   cc::Layer* ccLayer() override;
-  void setElementId(uint64_t id) override;
-  uint64_t elementId() const override;
+  void setElementId(cc::ElementId id) override;
+  cc::ElementId elementId() const override;
   void setCompositorMutableProperties(uint32_t properties) override;
   uint32_t compositorMutableProperties() const override;
 
   void setScrollParent(blink::WebLayer* parent) override;
   void setClipParent(blink::WebLayer* parent) override;
 
  protected:
   scoped_refptr<cc::Layer> layer_;
 
   bool contents_opaque_is_fixed_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(WebLayerImpl);
 };
 
 }  // namespace cc_blink
 
 #endif  // CC_BLINK_WEB_LAYER_IMPL_H_