Refactor cc scrollbar layers to separate solid-color vs desktop.

cc/layers/scrollbar_layer_base.cc

Index: cc/layers/scrollbar_layer_base.cc
diff --git a/cc/layers/scrollbar_layer_base.cc b/cc/layers/scrollbar_layer_base.cc
new file mode 100644
index 0000000000000000000000000000000000000000..d8cdba1ab71bc2f80476d71b7236d5a39628e00e
--- /dev/null
+++ b/cc/layers/scrollbar_layer_base.cc
@@ -0,0 +1,18 @@
+// Copyright 2012 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 "cc/layers/scrollbar_layer_base.h"
+
+#include "cc/layers/layer.h"
+
+namespace cc {
+
+ScrollbarLayerBase::~ScrollbarLayerBase() {}
+
+int ScrollbarLayerBase::scroll_layer_id() const { return scroll_layer_id_; }
+ScrollbarOrientation ScrollbarLayerBase::Orientation() const {
+  return orientation_;
+}
+
+}  // namespace cc