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

cc/cc.gyp

 # Copyright (c) 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.
 
 {
   'variables': {
     'chromium_code': 1,
     'cc_source_files': [
       'animation/animation.cc',
       'animation/animation.h',
@@ skipping 111 matching lines @@
       'layers/picture_layer_impl.cc',
       'layers/picture_layer_impl.h',
       'layers/quad_sink.h',
       'layers/render_pass_sink.h',
       'layers/render_surface.cc',
       'layers/render_surface.h',
       'layers/render_surface_impl.cc',
       'layers/render_surface_impl.h',
       'layers/scrollbar_layer.cc',
       'layers/scrollbar_layer.h',
+      'layers/scrollbar_layer_base.cc',
+      'layers/scrollbar_layer_base.h',
       'layers/scrollbar_layer_impl.cc',
       'layers/scrollbar_layer_impl.h',
+      'layers/scrollbar_layer_impl_base.cc',
+      'layers/scrollbar_layer_impl_base.h',
       'layers/solid_color_layer.cc',
       'layers/solid_color_layer.h',
       'layers/solid_color_layer_impl.cc',
       'layers/solid_color_layer_impl.h',
+      'layers/solid_color_scrollbar_layer.cc',
+      'layers/solid_color_scrollbar_layer.h',
+      'layers/solid_color_scrollbar_layer_impl.cc',
+      'layers/solid_color_scrollbar_layer_impl.h',
       'layers/texture_layer.cc',
       'layers/texture_layer.h',
       'layers/texture_layer_client.h',
       'layers/texture_layer_impl.cc',
       'layers/texture_layer_impl.h',
       'layers/tiled_layer.cc',
       'layers/tiled_layer.h',
       'layers/tiled_layer_impl.cc',
       'layers/tiled_layer_impl.h',
       'layers/video_frame_provider.h',
@@ skipping 225 matching lines @@
         'CC_IMPLEMENTATION=1',
       ],
       'sources': [
         '<@(cc_source_files)',
       ],
       # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
       'msvs_disabled_warnings': [ 4267, ],
     },
   ],
 }