diff -up chromium-58.0.3029.81/media/base/mime_util_internal.cc.mp3 chromium-58.0.3029.81/media/base/mime_util_internal.cc
--- chromium-58.0.3029.81/media/base/mime_util_internal.cc.mp3	2017-04-21 14:46:15.817743487 -0400
+++ chromium-58.0.3029.81/media/base/mime_util_internal.cc	2017-04-21 14:52:58.544150880 -0400
@@ -244,10 +244,10 @@ void MimeUtil::AddSupportedMediaFormats(
   CodecSet webm_codecs(webm_audio_codecs);
   webm_codecs.insert(webm_video_codecs.begin(), webm_video_codecs.end());
 
-#if BUILDFLAG(USE_PROPRIETARY_CODECS)
   CodecSet mp3_codecs;
   mp3_codecs.insert(MP3);
 
+#if BUILDFLAG(USE_PROPRIETARY_CODECS)
   CodecSet aac;
   aac.insert(MPEG2_AAC);
   aac.insert(MPEG4_AAC);
@@ -291,10 +291,10 @@ void MimeUtil::AddSupportedMediaFormats(
   AddContainerWithCodecs("application/ogg", ogg_codecs, false);
   AddContainerWithCodecs("audio/flac", implicit_codec, false);
 
-#if BUILDFLAG(USE_PROPRIETARY_CODECS)
   AddContainerWithCodecs("audio/mpeg", mp3_codecs, true);  // Allow "mp3".
   AddContainerWithCodecs("audio/mp3", implicit_codec, true);
   AddContainerWithCodecs("audio/x-mp3", implicit_codec, true);
+#if BUILDFLAG(USE_PROPRIETARY_CODECS)
   AddContainerWithCodecs("audio/aac", implicit_codec, true);  // AAC / ADTS.
   AddContainerWithCodecs("audio/mp4", mp4_audio_codecs, true);
   DCHECK(!mp4_video_codecs.empty());
@@ -715,7 +715,6 @@ bool MimeUtil::IsCodecProprietary(Codec
     case INVALID_CODEC:
     case AC3:
     case EAC3:
-    case MP3:
     case MPEG2_AAC:
     case MPEG4_AAC:
     case H264:
@@ -723,6 +722,7 @@ bool MimeUtil::IsCodecProprietary(Codec
     case DOLBY_VISION:
       return true;
 
+    case MP3:
     case PCM:
     case VORBIS:
     case OPUS:
diff -up chromium-58.0.3029.81/third_party/ffmpeg/ffmpeg_generated.gni.mp3 chromium-58.0.3029.81/third_party/ffmpeg/ffmpeg_generated.gni
--- chromium-58.0.3029.81/third_party/ffmpeg/ffmpeg_generated.gni.mp3	2017-04-21 11:49:42.000000000 -0400
+++ chromium-58.0.3029.81/third_party/ffmpeg/ffmpeg_generated.gni	2017-04-21 14:46:15.816743506 -0400
@@ -176,19 +176,12 @@ if ((is_linux && current_cpu == "arm" &&
   ]
 }
 
-if ((current_cpu == "x64" && ffmpeg_branding == "Chrome") || (is_android && current_cpu == "arm" && arm_use_neon && ffmpeg_branding == "Chrome") || (is_android && current_cpu == "arm64" && ffmpeg_branding == "Chrome") || (is_android && current_cpu == "mips64el" && ffmpeg_branding == "Chrome") || (is_android && current_cpu == "mipsel" && ffmpeg_branding == "Chrome") || (is_android && current_cpu == "x86" && ffmpeg_branding == "Chrome") || (is_linux && current_cpu == "arm" && arm_use_neon && ffmpeg_branding == "Chrome") || (is_linux && current_cpu == "arm" && arm_use_neon && ffmpeg_branding == "ChromeOS") || (is_linux && current_cpu == "arm" && ffmpeg_branding == "Chrome") || (is_linux && current_cpu == "arm" && ffmpeg_branding == "ChromeOS") || (is_linux && current_cpu == "arm64" && ffmpeg_branding == "Chrome") || (is_linux && current_cpu == "arm64" && ffmpeg_branding == "ChromeOS") || (is_linux && current_cpu == "mipsel" && ffmpeg_branding == "Chrome") || (is_linux && current_cpu == "mipsel" && ffmpeg_branding == "ChromeOS") || (is_linux && current_cpu == "x64" && ffmpeg_branding == "ChromeOS") || (is_linux && current_cpu == "x86" && ffmpeg_branding == "Chrome") || (is_linux && current_cpu == "x86" && ffmpeg_branding == "ChromeOS") || (is_win && ffmpeg_branding == "Chrome")) {
+if ((current_cpu == "x64") || (is_android && current_cpu == "arm" && arm_use_neon) || (is_android && current_cpu == "arm64") || (is_android && current_cpu == "mips64el") || (is_android && current_cpu == "mipsel") || (is_android && current_cpu == "x86") || (is_linux && current_cpu == "arm" && arm_use_neon) || (is_linux && current_cpu == "arm" && arm_use_neon) || (is_linux && current_cpu == "arm") || (is_linux && current_cpu == "arm64") || (is_linux && current_cpu == "mipsel") || (is_linux && current_cpu == "x64") || (is_linux && current_cpu == "x86") || (is_win))
+{
   ffmpeg_c_sources += [
-    "libavcodec/aac_ac3_parser.c",
-    "libavcodec/aac_parser.c",
-    "libavcodec/aacadtsdec.c",
-    "libavcodec/aacps_float.c",
-    "libavcodec/aacpsdsp_float.c",
-    "libavcodec/aacsbr.c",
-    "libavcodec/aactab.c",
-    "libavcodec/ac3tab.c",
-    "libavcodec/autorename_libavcodec_aacdec.c",
     "libavcodec/autorename_libavcodec_mpegaudiodsp.c",
     "libavcodec/autorename_libavcodec_sbrdsp.c",
+    "libavcodec/ac3tab.c",
     "libavcodec/cbrt_data.c",
     "libavcodec/dct.c",
     "libavcodec/dct32_fixed.c",
@@ -204,7 +197,6 @@ if ((current_cpu == "x64" && ffmpeg_bran
     "libavcodec/mpegaudiodsp_float.c",
     "libavcodec/sinewin.c",
     "libavcodec/sinewin_fixed.c",
-    "libavformat/aacdec.c",
     "libavformat/apetag.c",
     "libavformat/img2.c",
     "libavformat/mov.c",
@@ -213,6 +205,21 @@ if ((current_cpu == "x64" && ffmpeg_bran
   ]
 }
 
+if ((current_cpu == "x64" && ffmpeg_branding == "Chrome") || (is_android && current_cpu == "arm" && arm_use_neon && ffmpeg_branding == "Chrome") || (is_android && current_cpu == "arm64" && ffmpeg_branding == "Chrome") || (is_android && current_cpu == "mips64el" && ffmpeg_branding == "Chrome") || (is_android && current_cpu == "mipsel" && ffmpeg_branding == "Chrome") || (is_android && current_cpu == "x86" && ffmpeg_branding == "Chrome") || (is_linux && current_cpu == "arm" && arm_use_neon && ffmpeg_branding == "Chrome") || (is_linux && current_cpu == "arm" && arm_use_neon && ffmpeg_branding == "ChromeOS") || (is_linux && current_cpu == "arm" && ffmpeg_branding == "Chrome") || (is_linux && current_cpu == "arm" && ffmpeg_branding == "ChromeOS") || (is_linux && current_cpu == "arm64" && ffmpeg_branding == "Chrome") || (is_linux && current_cpu == "arm64" && ffmpeg_branding == "ChromeOS") || (is_linux && current_cpu == "mipsel" && ffmpeg_branding == "Chrome") || (is_linux && current_cpu == "mipsel" && ffmpeg_branding == "ChromeOS") || (is_linux && current_cpu == "x64" && ffmpeg_branding == "ChromeOS") || (is_linux && current_cpu == "x86" && ffmpeg_branding == "Chrome") || (is_linux && current_cpu == "x86" && ffmpeg_branding == "ChromeOS") || (is_win && ffmpeg_branding == "Chrome")) 
+{
+  ffmpeg_c_sources += [
+    "libavcodec/aac_ac3_parser.c",
+    "libavcodec/aac_parser.c",
+    "libavcodec/aacadtsdec.c",
+    "libavcodec/aacps_float.c",
+    "libavcodec/aacpsdsp_float.c",
+    "libavcodec/aacsbr.c",
+    "libavcodec/aactab.c",
+    "libavcodec/autorename_libavcodec_aacdec.c",
+    "libavformat/aacdec.c",
+  ]
+}
+
 if ((is_android && current_cpu == "x64") || (is_android && current_cpu == "x86") || (is_linux && current_cpu == "x64") || (is_linux && current_cpu == "x86") || (is_mac) || (is_win)) {
   ffmpeg_c_sources += [
     "libavcodec/x86/autorename_libavcodec_x86_vorbisdsp_init.c",
@@ -312,21 +319,31 @@ if ((is_linux && current_cpu == "x64") |
 if ((current_cpu == "x64" && ffmpeg_branding == "Chrome") || (is_android && current_cpu == "x86" && ffmpeg_branding == "Chrome") || (is_linux && current_cpu == "x64" && ffmpeg_branding == "ChromeOS") || (is_linux && current_cpu == "x86" && ffmpeg_branding == "Chrome") || (is_linux && current_cpu == "x86" && ffmpeg_branding == "ChromeOS") || (is_win && ffmpeg_branding == "Chrome")) {
   ffmpeg_c_sources += [
     "libavcodec/x86/aacpsdsp_init.c",
+   ]
+}
+
+if ((current_cpu == "x64") || (is_android && current_cpu == "x86") || (is_linux && current_cpu == "x64") || (is_linux && current_cpu == "x86") || (is_win)) {
+  ffmpeg_c_sources += [
     "libavcodec/x86/dct_init.c",
     "libavcodec/x86/mpegaudiodsp.c",
     "libavcodec/x86/sbrdsp_init.c",
   ]
 }
 
-if ((current_cpu == "x64" && ffmpeg_branding == "Chrome") || (is_linux && current_cpu == "x64" && ffmpeg_branding == "ChromeOS") || (is_linux && current_cpu == "x86" && ffmpeg_branding == "Chrome") || (is_linux && current_cpu == "x86" && ffmpeg_branding == "ChromeOS") || (is_win && ffmpeg_branding == "Chrome")) {
+if ((current_cpu == "x64") || (is_android && current_cpu == "x86") || (is_linux && current_cpu == "x64") || (is_linux && current_cpu == "x86") || (is_win)) {
   ffmpeg_yasm_sources += [
-    "libavcodec/x86/aacpsdsp.asm",
     "libavcodec/x86/dct32.asm",
     "libavcodec/x86/imdct36.asm",
     "libavcodec/x86/sbrdsp.asm",
   ]
 }
 
+if ((current_cpu == "x64" && ffmpeg_branding == "Chrome") || (is_linux && current_cpu == "x64" && ffmpeg_branding == "ChromeOS") || (is_linux && current_cpu == "x86" && ffmpeg_branding == "Chrome") || (is_linux && current_cpu == "x86" && ffmpeg_branding == "ChromeOS") || (is_win && ffmpeg_branding == "Chrome")) {
+  ffmpeg_yasm_sources += [
+    "libavcodec/x86/aacpsdsp.asm",
+  ]
+}
+
 if ((is_linux && current_cpu == "arm" && arm_use_neon) || (is_linux && current_cpu == "arm")) {
   ffmpeg_c_sources += [
     "libavcodec/arm/h264pred_init_arm.c",
diff -up chromium-58.0.3029.81/third_party/ffmpeg/libavcodec/sbrdsp.c.mp3 chromium-58.0.3029.81/third_party/ffmpeg/libavcodec/sbrdsp.c
--- chromium-58.0.3029.81/third_party/ffmpeg/libavcodec/sbrdsp.c.mp3	2017-04-21 11:49:43.000000000 -0400
+++ chromium-58.0.3029.81/third_party/ffmpeg/libavcodec/sbrdsp.c	2017-04-21 14:46:15.817743487 -0400
@@ -23,6 +23,7 @@
 #define USE_FIXED 0
 
 #include "aac.h"
+#include "aacsbrdata.h"
 #include "config.h"
 #include "libavutil/attributes.h"
 #include "libavutil/intfloat.h"