Re-add AC3/EAC3 audio demuxing support

content/browser/media/media_canplaytype_browsertest.cc

Index: content/browser/media/media_canplaytype_browsertest.cc
diff --git a/content/browser/media/media_canplaytype_browsertest.cc b/content/browser/media/media_canplaytype_browsertest.cc
index b44a3a1f752a71eb1916f6e7d20322aa81c55a92..9cbf595039d4f38c4bfd0e85e2451e00b98accee 100644
--- a/content/browser/media/media_canplaytype_browsertest.cc
+++ b/content/browser/media/media_canplaytype_browsertest.cc
@@ -1041,4 +1041,20 @@ IN_PROC_BROWSER_TEST_F(MediaCanPlayTypeTest, CodecSupportTest_HLS) {
   TestMPEGUnacceptableCombinations("application/vnd.apple.mpegurl");
 }
 
+#if defined(ENABLE_AC3_EAC3_DEMUXING)

[ddorwin, 2015/02/27 01:44:13]

We should always run the tests, but the expected results should be based on this
define.

[servolk, 2015/02/27 02:19:07]

Done.

+IN_PROC_BROWSER_TEST_F(MediaCanPlayTypeTest, CodecSupportTest_ac3_eac3) {
+  // AC3
+  EXPECT_EQ(kPropProbably, CanPlay("'audio/mp4; codecs=\"ac-3\"'"));

[ddorwin, 2015/02/27 01:44:13]

Please also test invalid variants, such as:
ac-2
ac-4
mp4a.a5.
mp4a.a5.1
mp4a.a7

If you put these in TestMPEGUnacceptableCombinations(), they'll run for all
relevant containers.

[servolk, 2015/02/27 02:19:07]

Ok, I've added a few variants, should be enough for basic coverage.

+  EXPECT_EQ(kPropProbably, CanPlay("'audio/mp4; codecs=\"mp4a.a5\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"ac-3\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"mp4a.a5\"'"));
+  // EAC3 aka DD+ aka Dolby Digital Plus
+  EXPECT_EQ(kPropProbably, CanPlay("'audio/mp4; codecs=\"ec-3\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'audio/mp4; codecs=\"mp4a.a6\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"ec-3\"'"));
+  EXPECT_EQ(kPropProbably, CanPlay("'video/mp4; codecs=\"mp4a.a6\"'"));

[ddorwin, 2015/02/27 01:44:13]

There are many more test scenarios. For example, x-m4a, HLS, etc. Please inline
these like the others. (By ifdef'ing the result, you won't need ifdefs
everywhere.)

[servolk, 2015/02/27 02:19:07]

What do you mean? I've basically taken one of the existing tests and changed it
to test ac3/eac3 codec variants.

[ddorwin, 2015/03/02 19:35:38]

The tests are broken up by container, not codec. If you add these ~10 lines to
each of the BMFF containers (video/mp4, x-m4a, HLS, etc.) you'll get more
complete coverage (and possibly see that you are enabling things you didn't
intend to). We also need to check that WebM does not support these codecs.

+}
+#endif
+}
+
 }  // namespace content