Workaround assembly offsets build error for WebRTC standalone.

libvpx.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': {
     'libvpx_build_vp9%': 1,
     'libvpx_source%': 'source/libvpx',
     'conditions': [
       ['os_posix==1', {
         'asm_obj_extension': 'o',
@@ skipping 468 matching lines @@
             },
           ],
           'sources': [
             '<(INTERMEDIATE_DIR)/vp8_asm_enc_offsets.obj',
           ],
         }, {
           'variables': {
             'unpack_lib_search_path_list': [
               '-a', '<(PRODUCT_DIR)/libvpx_asm_offsets_vp8.a',
               '-a', '<(LIB_DIR)/third_party/libvpx/libvpx_asm_offsets_vp8.a',
+              '-a', '<(LIB_DIR)/chromium/src/third_party/libvpx/libvpx_asm_offsets_vp8.a',
               '-a', '<(LIB_DIR)/Source/WebKit/chromium/third_party/libvpx/libvpx_asm_offsets_vp8.a',
               '-a', '<(lib_intermediate_name)',
             ],
             'unpack_lib_output_dir':'<(INTERMEDIATE_DIR)',
             'unpack_lib_name':'vp8_asm_enc_offsets.o'
           },
           'includes': ['unpack_lib_posix.gypi'],
           # Need this otherwise gyp won't run the rule on them.
           'sources': [
             '<(INTERMEDIATE_DIR)/vp8_asm_enc_offsets.o',
@@ skipping 53 matching lines @@
             },
           ],
           'sources': [
             '<(INTERMEDIATE_DIR)/vpx_scale_asm_offsets.obj',
           ],
         }, {
           'variables': {
             'unpack_lib_search_path_list': [
               '-a', '<(PRODUCT_DIR)/libvpx_asm_offsets_vpx_scale.a',
               '-a', '<(LIB_DIR)/third_party/libvpx/libvpx_asm_offsets_vpx_scale.a',
+              '-a', '<(LIB_DIR)/chromium/src/third_party/libvpx/libvpx_asm_offsets_vpx_scale.a',
               '-a', '<(LIB_DIR)/Source/WebKit/chromium/third_party/libvpx/libvpx_asm_offsets_vpx_scale.a',
               '-a', '<(lib_intermediate_name)',
             ],
             'unpack_lib_output_dir':'<(INTERMEDIATE_DIR)',
             'unpack_lib_name':'vpx_scale_asm_offsets.o'
           },
           'includes': ['unpack_lib_posix.gypi'],
          # Need this otherwise gyp won't run the rule on them.
           'sources': [
             '<(INTERMEDIATE_DIR)/vpx_scale_asm_offsets.o',
           ],
         }],
       ],
       'includes': ['obj_int_extract.gypi'],
     },
   ],
 }