Remove third_party/golang.org/x/mobile as it is no longer used with Go 1.5.

third_party/go/src/golang.org/x/mobile/app/android_x86.c

Index: third_party/go/src/golang.org/x/mobile/app/android_x86.c
diff --git a/third_party/go/src/golang.org/x/mobile/app/android_x86.c b/third_party/go/src/golang.org/x/mobile/app/android_x86.c
deleted file mode 100644
index 6393422aff49574d51e080c7610f24992a2a1c94..0000000000000000000000000000000000000000
--- a/third_party/go/src/golang.org/x/mobile/app/android_x86.c
+++ /dev/null
@@ -1,38 +0,0 @@
-// Copyright 2014 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// +build android,x86
-
-#include <android/log.h>
-#include <dlfcn.h>
-#include <errno.h>
-#include <fcntl.h>
-#include <stdlib.h>
-#include <stdint.h>
-#include <string.h>
-#include "_cgo_export.h"
-
-void build_auxv(uint32_t *xauxv, size_t xauxv_len) {
-	char* auxv = (char*)xauxv;
-	size_t auxv_len = xauxv_len*sizeof(uint32_t);
-
-	// TODO(crawshaw): determine if we can read /proc/self/auxv on
-	//                 x86 android release builds.
-	int fd = open("/proc/self/auxv", O_RDONLY, 0);
-	if (fd == -1) {
-		__android_log_print(ANDROID_LOG_FATAL, "Go", "cannot open /proc/self/auxv: %s", strerror(errno));
-	}
-	int n = read(fd, &auxv, auxv_len);
-	if (n < 0) {
-		__android_log_print(ANDROID_LOG_FATAL, "Go", "error reading /proc/self/auxv: %s", strerror(errno));
-	}
-	if (n == auxv_len) { // auxv should be more than plenty.
-		__android_log_print(ANDROID_LOG_FATAL, "Go", "/proc/self/auxv too big");
-	}
-	close(fd);
-
-	for (; n < auxv_len; n++) {
-		auxv[n] = 0;
-	}
-}