Implement pinch-zoom scaling for main-frame scrollbars and pinch-zoom overlay scrollbars.

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': {
     'cc_source_files': [
       'active_animation.cc',
       'active_animation.h',
       'animation_curve.cc',
@@ skipping 126 matching lines @@
       'picture_layer_impl.cc',
       'picture_layer_impl.h',
       'picture_layer_tiling.cc',
       'picture_layer_tiling.h',
       'picture_layer_tiling_set.cc',
       'picture_layer_tiling_set.h',
       'picture_pile.cc',
       'picture_pile.h',
       'picture_pile_impl.cc',
       'picture_pile_impl.h',
+      'pinch_zoom_scrollbar_layer.cc',
+      'pinch_zoom_scrollbar_layer.h',
+      'pinch_zoom_scrollbars_manager.cc',
+      'pinch_zoom_scrollbars_manager.h',
       'platform_color.h',
       'prioritized_resource.cc',
       'prioritized_resource.h',
       'prioritized_resource_manager.cc',
       'prioritized_resource_manager.h',
       'priority_calculator.cc',
       'priority_calculator.h',
       'program_binding.cc',
       'program_binding.h',
       'proxy.cc',
@@ skipping 150 matching lines @@
       ],
       'all_dependent_settings': {
         'include_dirs': [
           # Needed for <public/WebTransformationMatrix.h> in layer.h
           '<(webkit_src_dir)/Source/Platform/chromium',
         ],
       }
     },
   ],
 }