Fix visibility of sanitizer config on CrOS.

The GN roll in https://crrev.com/c/2360685 started
enforcing visibility of configs, and this caused
the compile to break on 'ChromiumOS ASAN Release'.
This CL fixes the visibility rule accordingly.

Bug: 1132431
Change-Id: Ic702f7a48b4de80a5dba46345ced9f9d9220763d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2432670Reviewed-by: Max Moroz <mmoroz@chromium.org>
Commit-Queue: Dirk Pranke <dpranke@google.com>
Cr-Commit-Position: refs/heads/master@{#810928}

build/config/sanitizers/BUILD.gn

@@ -148,6 +148,9 @@ config("default_sanitizer_ldflags") {
   visibility = [
     ":default_sanitizer_flags",
     ":deps",
+
+    # https://crbug.com/360158.
+    "//tools/ipc_fuzzer/fuzzer:ipc_fuzzer",
   ]
 
   if (is_posix || is_fuchsia) {
@@ -432,7 +435,8 @@ config("lsan_flags") {
 
 config("msan_flags") {
   if (is_msan) {
-    assert(is_linux || is_chromeos, "msan only supported on linux x86_64/ChromeOS")
+    assert(is_linux || is_chromeos,
+           "msan only supported on linux x86_64/ChromeOS")
     if (!defined(msan_blacklist_path)) {
       msan_blacklist_path =
           rebase_path("//tools/msan/blacklist.txt", root_build_dir)