Cherry-pick "Use lrand48 on Android" [DO NOT MERGE]

Also remove from x86/libvpx_srcs.txt
Original change: https://gerrit.chromium.org/gerrit/70494/

When building x86 assembly use lrand48 instead of the
undocumented inlined _rand function.

Android now supports rand()
https://android-review.googlesource.com/97731
but only for new versions. Original workaround:
https://gerrit.chromium.org/gerrit/15744

(cherry-picked from 614a6a21483b59b4ab557785c160c8ca4722b062)

Change-Id: I3c17cf37c40623f8353d8836fb4ac02c35a4d8b8
diff --git a/libvpx/vp8/common/x86/postproc_mmx.asm b/libvpx/vp8/common/x86/postproc_mmx.asm
index 8be3431..a2b1632 100644
--- a/libvpx/vp8/common/x86/postproc_mmx.asm
+++ b/libvpx/vp8/common/x86/postproc_mmx.asm
@@ -246,7 +246,6 @@
 ;                            unsigned char whiteclamp[16],
 ;                            unsigned char bothclamp[16],
 ;                            unsigned int Width, unsigned int Height, int Pitch)
-extern sym(rand)
 global sym(vp8_plane_add_noise_mmx) PRIVATE
 sym(vp8_plane_add_noise_mmx):
     push        rbp
@@ -258,7 +257,7 @@
     ; end prolog
 
 .addnoise_loop:
-    call sym(rand) WRT_PLT
+    call sym(LIBVPX_RAND) WRT_PLT
     mov     rcx, arg(1) ;noise
     and     rax, 0xff
     add     rcx, rax
diff --git a/libvpx/vp8/common/x86/postproc_sse2.asm b/libvpx/vp8/common/x86/postproc_sse2.asm
index f53daa7..fed4ee5 100644
--- a/libvpx/vp8/common/x86/postproc_sse2.asm
+++ b/libvpx/vp8/common/x86/postproc_sse2.asm
@@ -660,7 +660,6 @@
 ;                            unsigned char whiteclamp[16],
 ;                            unsigned char bothclamp[16],
 ;                            unsigned int Width, unsigned int Height, int Pitch)
-extern sym(rand)
 global sym(vp8_plane_add_noise_wmt) PRIVATE
 sym(vp8_plane_add_noise_wmt):
     push        rbp
@@ -672,7 +671,7 @@
     ; end prolog
 
 .addnoise_loop:
-    call sym(rand) WRT_PLT
+    call sym(LIBVPX_RAND) WRT_PLT
     mov     rcx, arg(1) ;noise
     and     rax, 0xff
     add     rcx, rax
diff --git a/libvpx/vp8/common/x86/postproc_x86.c b/libvpx/vp8/common/x86/postproc_x86.c
deleted file mode 100644
index 3ec0106..0000000
--- a/libvpx/vp8/common/x86/postproc_x86.c
+++ /dev/null
@@ -1,24 +0,0 @@
-/*
- *  Copyright (c) 2012 The WebM project authors. All Rights Reserved.
- *
- *  Use of this source code is governed by a BSD-style license
- *  that can be found in the LICENSE file in the root of the source
- *  tree. An additional intellectual property rights grant can be found
- *  in the file PATENTS.  All contributing project authors may
- *  be found in the AUTHORS file in the root of the source tree.
- */
-
-/* On Android NDK, rand is inlined function, but postproc needs rand symbol */
-#if defined(__ANDROID__)
-#define rand __rand
-#include <stdlib.h>
-#undef rand
-
-extern int rand(void)
-{
-  return __rand();
-}
-#else
-/* ISO C forbids an empty translation unit. */
-int vp8_unused;
-#endif
diff --git a/libvpx/vp8/vp8_common.mk b/libvpx/vp8/vp8_common.mk
index dfb54a5..8b49eff 100644
--- a/libvpx/vp8/vp8_common.mk
+++ b/libvpx/vp8/vp8_common.mk
@@ -108,7 +108,6 @@
 VP8_COMMON_SRCS-$(HAVE_SSE4_1) += common/x86/sad_sse4.asm
 
 ifeq ($(CONFIG_POSTPROC),yes)
-VP8_COMMON_SRCS-$(ARCH_X86)$(ARCH_X86_64) += common/x86/postproc_x86.c
 VP8_COMMON_SRCS-$(HAVE_MMX) += common/x86/postproc_mmx.asm
 VP8_COMMON_SRCS-$(HAVE_SSE2) += common/x86/mfqe_sse2.asm
 VP8_COMMON_SRCS-$(HAVE_SSE2) += common/x86/postproc_sse2.asm
diff --git a/libvpx/vp9/common/x86/vp9_postproc_mmx.asm b/libvpx/vp9/common/x86/vp9_postproc_mmx.asm
index c2118db..5b8deef 100644
--- a/libvpx/vp9/common/x86/vp9_postproc_mmx.asm
+++ b/libvpx/vp9/common/x86/vp9_postproc_mmx.asm
@@ -464,7 +464,6 @@
 ;                            unsigned char whiteclamp[16],
 ;                            unsigned char bothclamp[16],
 ;                            unsigned int width, unsigned int height, int pitch)
-extern sym(rand)
 global sym(vp9_plane_add_noise_mmx) PRIVATE
 sym(vp9_plane_add_noise_mmx):
     push        rbp
@@ -476,7 +475,7 @@
     ; end prolog
 
 .addnoise_loop:
-    call sym(rand) WRT_PLT
+    call sym(LIBVPX_RAND) WRT_PLT
     mov     rcx, arg(1) ;noise
     and     rax, 0xff
     add     rcx, rax
diff --git a/libvpx/vp9/common/x86/vp9_postproc_sse2.asm b/libvpx/vp9/common/x86/vp9_postproc_sse2.asm
index 858fc99..ec8bfdb 100644
--- a/libvpx/vp9/common/x86/vp9_postproc_sse2.asm
+++ b/libvpx/vp9/common/x86/vp9_postproc_sse2.asm
@@ -629,7 +629,6 @@
 ;                            unsigned char whiteclamp[16],
 ;                            unsigned char bothclamp[16],
 ;                            unsigned int width, unsigned int height, int pitch)
-extern sym(rand)
 global sym(vp9_plane_add_noise_wmt) PRIVATE
 sym(vp9_plane_add_noise_wmt):
     push        rbp
@@ -641,7 +640,7 @@
     ; end prolog
 
 .addnoise_loop:
-    call sym(rand) WRT_PLT
+    call sym(LIBVPX_RAND) WRT_PLT
     mov     rcx, arg(1) ;noise
     and     rax, 0xff
     add     rcx, rax
diff --git a/libvpx/vpx_ports/x86_abi_support.asm b/libvpx/vpx_ports/x86_abi_support.asm
index eccbfa3..3814ef4 100644
--- a/libvpx/vpx_ports/x86_abi_support.asm
+++ b/libvpx/vpx_ports/x86_abi_support.asm
@@ -393,3 +393,14 @@
 section .text
 %endif
 
+; On Android platforms use lrand48 when building postproc routines. Prior to L
+; rand() was not available.
+%if CONFIG_POSTPROC=1
+%ifdef __ANDROID__
+extern sym(lrand48)
+%define LIBVPX_RAND lrand48
+%else
+extern sym(rand)
+%define LIBVPX_RAND rand
+%endif
+%endif ; CONFIG_POSTPROC
diff --git a/x86/libvpx_srcs.txt b/x86/libvpx_srcs.txt
index 0c59ce9..0d43a86 100644
--- a/x86/libvpx_srcs.txt
+++ b/x86/libvpx_srcs.txt
@@ -80,7 +80,6 @@
 vp8/common/x86/mfqe_sse2.asm
 vp8/common/x86/postproc_mmx.asm
 vp8/common/x86/postproc_sse2.asm
-vp8/common/x86/postproc_x86.c
 vp8/common/x86/recon_mmx.asm
 vp8/common/x86/recon_sse2.asm
 vp8/common/x86/recon_wrapper_sse2.c