Make CanPlayType return "probably" for HI10P h264 videos.

media/base/mime_util_internal.cc

Index: media/base/mime_util_internal.cc
diff --git a/media/base/mime_util_internal.cc b/media/base/mime_util_internal.cc
index b2904e8764d39bbc885ffed536481feb6cd3b7da..f7883e0d95044318f12c5da197970086a20b5fb6 100644
--- a/media/base/mime_util_internal.cc
+++ b/media/base/mime_util_internal.cc
@@ -281,7 +281,7 @@ SupportsType MimeUtil::AreSupportedCodecs(
   for (size_t i = 0; i < codecs.size(); ++i) {
     bool is_ambiguous = true;
     Codec codec = INVALID_CODEC;
-    if (!StringToCodec(codecs[i], &codec, &is_ambiguous))
+    if (!StringToCodec(codecs[i], &codec, &is_ambiguous, is_encrypted))
       return IsNotSupported;
 
     if (!IsCodecSupported(codec, mime_type_lower_case, is_encrypted) ||
@@ -322,7 +322,7 @@ void MimeUtil::InitializeMimeTypeMaps() {
     for (size_t j = 0; j < mime_type_codecs.size(); ++j) {
       Codec codec = INVALID_CODEC;
       bool is_ambiguous = true;
-      CHECK(StringToCodec(mime_type_codecs[j], &codec, &is_ambiguous));
+      CHECK(StringToCodec(mime_type_codecs[j], &codec, &is_ambiguous, false));
       DCHECK(!is_ambiguous);
       codecs.insert(codec);
     }
@@ -531,7 +531,8 @@ bool MimeUtil::IsCodecSupportedOnPlatform(
 
 bool MimeUtil::StringToCodec(const std::string& codec_id,
                              Codec* codec,
-                             bool* is_ambiguous) const {
+                             bool* is_ambiguous,
+                             bool is_encrypted) const {
   StringToCodecMappings::const_iterator itr =
       string_to_codec_map_.find(codec_id);
   if (itr != string_to_codec_map_.end()) {
@@ -554,10 +555,28 @@ bool MimeUtil::StringToCodec(const std::string& codec_id,
   uint8_t level_idc = 0;
   if (ParseAVCCodecId(codec_id, &profile, &level_idc)) {
     *codec = MimeUtil::H264;
-    *is_ambiguous =
-        (profile != H264PROFILE_BASELINE && profile != H264PROFILE_MAIN &&
-         profile != H264PROFILE_HIGH) ||
-        !IsValidH264Level(level_idc);
+    switch (profile) {
+// HIGH10PROFILE is supported through fallback to the ffmpeg decoder.

[ddorwin, 2016/03/31 22:31:12]

nit: , which

[hubbe, 2016/04/01 00:20:59]

Done.

+// Which is not available on Android, chromium builds or if

[ddorwin, 2016/03/31 22:31:12]

Chromium is irrelevant to this (that's handled elsewhere) and no different than
the other profiles, so I'd drop that part.

[hubbe, 2016/04/01 00:20:58]

Done.

+// FFMPEG has been disabled.

[ddorwin, 2016/03/31 22:31:12]

nit suggestion: s/has been disabled/is not used/. The former makes it sound like
it's an option.

[hubbe, 2016/04/01 00:20:59]

Done.

+#if !defined(MEDIA_DISABLE_FFMPEG) && !defined(OS_ANDROID)

[ddorwin, 2016/03/31 22:31:12]

:) +dalecurtis to confirm this logic.

We should probably make this more obvious when switching to build flags.

[DaleCurtis, 2016/03/31 22:58:44]

this is correct. android doesn't have ff_h264. 

[hubbe, 2016/04/01 00:20:59]

Acknowledged.

[hubbe, 2016/04/01 00:20:59]

Acknowledged.

+      case H264PROFILE_HIGH10PROFILE:

[ddorwin, 2016/03/31 22:31:12]

It might be nicer to always have this case and put the #if inside it. That does
require a #else to break, though.

[hubbe, 2016/04/01 00:20:58]

Tried it, but I didn't like how it turned out.

+        if (is_encrypted) {
+          // Currently we do not support EME on 10-bit videos.

[ddorwin, 2016/03/31 22:31:12]

More accurately, especially since we don't return false:
FFmpeg is not generally used for encrypted videos, so we do not know whether
10-bit is supported.

[hubbe, 2016/04/01 00:20:59]

Done.

+          *is_ambiguous = true;
+          break;
+        }

[ddorwin, 2016/03/31 22:31:12]

Add an explicit comment to "fall through" so it's clear this is not a bug. :)

[hubbe, 2016/04/01 00:20:59]

Done.

+#endif
+
+      case H264PROFILE_BASELINE:
+      case H264PROFILE_MAIN:
+      case H264PROFILE_HIGH:
+
+        *is_ambiguous = !IsValidH264Level(level_idc);
+        break;
+      default:
+        *is_ambiguous = true;
+    }
     return true;
   }