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

third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.cpp

Index: third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.cpp
diff --git a/third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.cpp b/third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.cpp
index 206782a6454c44ec37bdf59615489fea93970959..3f9a92ddb8f18cfa15be3705912948d9eaa169a6 100644
--- a/third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.cpp
@@ -77,7 +77,7 @@ static CompositorElementId CreateDomNodeBasedCompositorElementId(
   // TODO(wkorman): Centralize this implementation with similar across
   // animation, scrolling and compositing logic.
   return CreateCompositorElementId(DOMNodeIds::IdForNode(object.GetNode()),
-                                   CompositorSubElementId::kPrimary);
+                                   CompositorElementIdNamespace::kPrimary);
 }
 
 // True if a new property was created or a main thread scrolling reason changed