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

third_party/WebKit/Source/web/tests/VisualViewportTest.cpp

 // 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.
 
 #include "core/frame/VisualViewport.h"
 
 #include "core/dom/Document.h"
 #include "core/frame/BrowserControls.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
@@ skipping 763 matching lines @@
   EXPECT_SIZE_EQ(FloatSize(50, 60), visual_viewport.GetScrollOffset());
   EXPECT_EQ(2, visual_viewport.Scale());
 
   // Navigate again, this time the FrameView should be smaller.
   RegisterMockedHttpURLLoad("viewport-device-width.html");
   NavigateTo(base_url_ + "viewport-device-width.html");
 
   // Ensure the scroll layer matches the frame view's size.
   EXPECT_SIZE_EQ(FloatSize(320, 240), visual_viewport.ScrollLayer()->Size());
 
-  EXPECT_EQ(CompositorSubElementId::kViewport,
-            SubElementIdFromCompositorElementId(
+  EXPECT_EQ(CompositorElementIdNamespace::kViewport,
+            NamespaceFromCompositorElementId(
                 visual_viewport.ScrollLayer()->GetElementId()));
 
   // Ensure the location and scale were reset.
   EXPECT_SIZE_EQ(FloatSize(), visual_viewport.GetScrollOffset());
   EXPECT_EQ(1, visual_viewport.Scale());
 }
 
 // The main FrameView's size should be set such that its the size of the visual
 // viewport at minimum scale. Test that the FrameView is appropriately sized in
 // the presence of a viewport <meta> tag.
@@ skipping 1659 matching lines @@
                                    "    margin: 0px;"
                                    "  }"
                                    "  div { height:110vh; width: 110vw; }"
                                    "</style>"
                                    "<div></div>",
                                    base_url);
 }
 
 }  // namespace
 }  // namespace blink