Update FLAC to 1.3.1

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index 68719eb05e2e9028f503becdc52a8fd9fd02b479..ae81550588b2888ecfe1f02362e2dd5f33ab743b 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -34,6 +34,9 @@ source_set("flac") {
     "include/FLAC/stream_decoder.h",
     "include/FLAC/stream_encoder.h",
     "include/share/alloc.h",
+    "include/share/compat.h",
+    "include/share/endswap.h",
+    "include/share/private.h",
     "src/libFLAC/alloc.c",
     "src/libFLAC/bitmath.c",
     "src/libFLAC/bitreader.c",
@@ -60,9 +63,11 @@ source_set("flac") {
     "src/libFLAC/include/private/float.h",
     "src/libFLAC/include/private/format.h",
     "src/libFLAC/include/private/lpc.h",
+    "src/libFLAC/include/private/macros.h",
     "src/libFLAC/include/private/md5.h",
     "src/libFLAC/include/private/memory.h",
     "src/libFLAC/include/private/metadata.h",
+    "src/libFLAC/include/private/stream_encoder.h",
     "src/libFLAC/include/private/stream_encoder_framing.h",
     "src/libFLAC/include/private/window.h",
     "src/libFLAC/include/protected/all.h",
@@ -85,6 +90,24 @@ source_set("flac") {
 
   defines = [
     "FLAC__OVERFLOW_DETECT",
-    "VERSION=\"1.2.1\"",
+    "VERSION=\"1.3.1\"",
+    "HAVE_LROUND",
   ]
+
+  if (is_win) {
+    sources += [
+      "include/share/win_utf8_io.h",
+      "src/share/win_utf8_io/win_utf8_io.c",
+    ]
+    # win_utf8_io.c defines this itself.
+    configs -= [ "//build/config/win:lean_and_mean" ]
+    cflags = [
+      "/wd4334",  # 32-bit shift converted to 64 bits.
+      "/wd4267"   # Converting from size_t to unsigned on 64-bit.
+    ]
+  } else {
+    defines += [
+      "HAVE_INTTYPES_H",
+    ]
+  }
 }