[Android] Port Scroller.java to C++ and use for fling animations

content/content_child.gypi

 # Copyright 2013 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.
 
 {
   'dependencies': [
     '../base/base.gyp:base',
     '../components/tracing.gyp:tracing',
     '../skia/skia.gyp:skia',
     '../ui/gfx/gfx.gyp:gfx',
     '../ui/gfx/gfx.gyp:gfx_geometry',
     '../ui/ui.gyp:ui',
     '../url/url.gyp:url_lib',
   ],
   'include_dirs': [
     '..',
   ],
   'export_dependent_settings': [
     '../base/base.gyp:base',
   ],
   'sources': [
-    'child/android/child_jni_registrar.cc',
-    'child/android/child_jni_registrar.h',
     'child/appcache/appcache_backend_proxy.cc',
     'child/appcache/appcache_backend_proxy.h',
     'child/appcache/appcache_dispatcher.cc',
     'child/appcache/appcache_dispatcher.h',
     'child/appcache/appcache_frontend_impl.cc',
     'child/appcache/appcache_frontend_impl.h',
     'child/appcache/web_application_cache_host_impl.cc',
     'child/appcache/web_application_cache_host_impl.h',
     'child/blink_glue.cc',
     'child/blink_glue.h',
@@ skipping 190 matching lines @@
         'child/npapi/webplugin_delegate_impl_mac.mm',
       ],
     }],
     ['OS=="win"', {
       'sources!': [
         'child/npapi/webplugin_delegate_impl_aura.cc',
       ],
     }],
   ],
 }