Fix Android x86 builds of libvpx

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 70 matching lines @@
           'variables': {
             'yasm_output_path': '<(SHARED_INTERMEDIATE_DIR)/third_party/libvpx',
             'OS_CATEGORY%': '<(OS_CATEGORY)',
             'yasm_flags': [
               '-D', 'CHROMIUM',
               '-I', 'source/config/<(OS_CATEGORY)/<(target_arch_full)',
               '-I', 'source/config',
               '-I', '<(libvpx_source)',
               '-I', '<(shared_generated_dir)', # Generated assembly offsets
             ],
+            # yasm only gets the flags we define. It doesn't inherit any of the
+            # really useful defines that come with a gcc invocation. In this
+            # case, we rely on __ANDROID__ to set 'rand' to 'lrand48'.
+            # Previously we used the builtin _rand but that's gone away.
+            'conditions': [
+              ['OS=="android"', {
+                'yasm_flags': [
+                  '-D', '__ANDROID__',
+                ],
+              }],
+            ],
           },
           'dependencies': [
             'gen_asm_offsets_vp8',
           ],
           'includes': [
             '../yasm/yasm_compile.gypi'
           ],
           'include_dirs': [
             'source/config/<(OS_CATEGORY)/<(target_arch_full)',
             'source/config',
@@ skipping 481 matching lines @@
          # Need this otherwise gyp won't run the rule on them.
           'sources': [
             '<(INTERMEDIATE_DIR)/vpx_scale_asm_offsets.o',
           ],
         }],
       ],
       'includes': ['obj_int_extract.gypi'],
     },
   ],
 }