Make video codec support logic overridable via MediaClient

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 72b54be5c895bb5da06654acb96bf94fb78ad5f2..383975cedb99d84d725a19780a8ccae8cfc9d096 100644
--- a/content/browser/media/media_canplaytype_browsertest.cc
+++ b/content/browser/media/media_canplaytype_browsertest.cc
@@ -44,14 +44,6 @@ const char* kHlsProbably = kPropProbably;
 const char* kHlsMaybe = kPropMaybe;
 #endif  // !OS_ANDROID
 
-#if BUILDFLAG(ENABLE_HEVC_DEMUXING)
-// TODO(servolk): Change this to kPropProbably after adding platform-level
-// checks for HEVC codec ids. crbug.com/601949
-const char* kHevcSupported = kPropMaybe;
-#else
-const char* kHevcSupported = kNot;
-#endif
-
 #if BUILDFLAG(ENABLE_MSE_MPEG2TS_STREAM_PARSER)
 const char* kMp2tsMaybe = kPropMaybe;
 const char* kMp2tsProbably = kPropProbably;
@@ -758,11 +750,12 @@ IN_PROC_BROWSER_TEST_F(MediaCanPlayTypeTest, CodecSupportTest_mp4) {
   EXPECT_EQ(kPropMaybe,
             CanPlay("'video/mp4; codecs=\"avc3.42E01E, mp4a.40\"'"));
 
-  EXPECT_EQ(kHevcSupported, CanPlay("'video/mp4; codecs=\"hev1.1.6.L93.B0\"'"));
-  EXPECT_EQ(kHevcSupported, CanPlay("'video/mp4; codecs=\"hvc1.1.6.L93.B0\"'"));
-  EXPECT_EQ(kHevcSupported,
+  // HEVC is currently not supported in Chromium.

[ddorwin, 2016/07/20 23:26:24]

Do these test pass on implementations that do have
BUILDFLAG(ENABLE_HEVC_DEMUXING) and a corresponding MediaClient?

(I'm also wondering how we'll run tests when we start detecting VP9 profiles,
etc.)

Regarding the text, IIRC we use "Chrome" when referring to the browser. Also,
"currently" can probably be dropped.

[servolk, 2016/07/20 23:50:41]

There's no custom Chromecast MediaClient yet, I'm working on it in a separate CL
https://codereview.chromium.org/2156193003/ (although I wanted to inherit it
from the content::RenderMediaClient to avoid duplicating functions other than
IsSupportedVideoConfig and ran into some deps issues, looking into how to fix
that). But yes, you are right this would fail on platforms that do support HEVC
once we add the custom media client. I guess we could remove the HEVC tests from
this file completely and move it to Chromecast internal code, where we'll be
able to tell the actual expected outcome based on which platform we are running.

[ddorwin, 2016/07/22 00:40:51]

No, we shouldn't remove these tests. They at least provide negative coverage for
Chrome. Also, you will eventually want them. We will need to figure out how to
specify the expectations for such tests or override the results somehow.

Until then, I think it's probably better to leave kHevcSupported, even if it =
kNot, and add a TODO to figure this out where it is defined.

[servolk, 2016/07/22 03:06:28]

Done (restored the kHevcSupported)

+  EXPECT_EQ(kNot, CanPlay("'video/mp4; codecs=\"hev1.1.6.L93.B0\"'"));

[ddorwin, 2016/07/20 23:26:24]

What does encrypted_media_supported_types_browsertest.cc do? It appears
BUILDFLAG(ENABLE_HEVC_DEMUXING) would include HEVC codecs, but those should have
failed since is_ambiguous was true.

[servolk, 2016/07/20 23:50:41]

Hmm, looks like somehow these don't get run at all on cast_shell trybots. At
least I can't find the 'EncryptedMediaSupportedTypes' substring anywhere in the
cast_shell trybot log
(https://build.chromium.org/p/tryserver.chromium.linux/builders/cast_shell_lin...).
I wonder if we have custom encrypted media tests for Cast, I'll research more
and ask Luke.

+  EXPECT_EQ(kNot, CanPlay("'video/mp4; codecs=\"hvc1.1.6.L93.B0\"'"));
+  EXPECT_EQ(kNot,
             CanPlay("'video/mp4; codecs=\"hev1.1.6.L93.B0, mp4a.40.5\"'"));
-  EXPECT_EQ(kHevcSupported,
+  EXPECT_EQ(kNot,
             CanPlay("'video/mp4; codecs=\"hvc1.1.6.L93.B0, mp4a.40.5\"'"));
 
   // Note: set to kPropProbably when switches::kEnableVp9InMp4 is enabled by