Fix cc scrollbar layer issues with initialization, and use element ids throughout.

third_party/WebKit/Source/core/frame/VisualViewport.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 345 matching lines @@
   // set inner viewport container layer size.
   inner_viewport_container_layer_->SetMasksToBounds(
       GetPage().GetSettings().GetMainFrameClipsContent());
   inner_viewport_container_layer_->SetSize(FloatSize(size_));
 
   inner_viewport_scroll_layer_->PlatformLayer()->SetScrollClipLayer(
       inner_viewport_container_layer_->PlatformLayer());
   inner_viewport_scroll_layer_->PlatformLayer()->SetUserScrollable(true, true);
   if (MainFrame()) {
     if (Document* document = MainFrame()->GetDocument()) {
-      inner_viewport_scroll_layer_->SetElementId(CreateCompositorElementId(
-          DOMNodeIds::IdForNode(document), CompositorSubElementId::kViewport));
+      inner_viewport_scroll_layer_->SetElementId(
+          CreateCompositorElementId(DOMNodeIds::IdForNode(document),
+                                    CompositorElementIdNamespace::kViewport));
     }
   }
 
   root_transform_layer_->AddChild(inner_viewport_container_layer_.get());
   inner_viewport_container_layer_->AddChild(overscroll_elasticity_layer_.get());
   overscroll_elasticity_layer_->AddChild(page_scale_layer_.get());
   page_scale_layer_->AddChild(inner_viewport_scroll_layer_.get());
 
   // Ensure this class is set as the scroll layer's ScrollableArea.
   coordinator->ScrollableAreaScrollLayerDidChange(this);
@@ skipping 478 matching lines @@
   } else if (graphics_layer == root_transform_layer_.get()) {
     name = "Root Transform Layer";
   } else {
     NOTREACHED();
   }
 
   return name;
 }
 
 }  // namespace blink