Add 2 missing neon files for the android build

gyp/libwebp.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': {
     'use_system_libwebp%': 0,
   },
   'conditions': [
     ['use_system_libwebp==0', {
@@ skipping 56 matching lines @@
         {
           'target_name': 'libwebp_dsp_neon',
           'conditions': [
             ['armv7 == 1', {
               'type': 'static_library',
               'include_dirs': [
                   '../third_party/externals/libwebp',
               ],
               'sources': [
                 '../third_party/externals/libwebp/src/dsp/dec_neon.c',
+                '../third_party/externals/libwebp/src/dsp/enc_neon.c',
+                '../third_party/externals/libwebp/src/dsp/upsampling_neon.c',
               ],
               # behavior similar dsp_neon.c.neon in an Android.mk
               'cflags!': [
                 '-mfpu=vfpv3-d16',
               ],
               'cflags': [ '-mfpu=neon' ],
             },{  # "armv7 != 1"
               'type': 'none',
             }],
           ],
@@ skipping 78 matching lines @@
           'link_settings': {
             'libraries': [
               '-lwebp',
             ],
           },
         }
       ],
     }],
   ],
 }