Place inband text track support behind a flag.

The inband text track support is not ready to be exposed by default. This
patch adds a flag for enabling this feature and fixes the code to ignore
text tracks when the flag is not set.

BUG=230708
TEST=WebMTracksParserTest.TestIgnoringTextTracks

Review URL: https://chromiumcodereview.appspot.com/18104002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@209320 0039d316-1c4b-4281-b951-d872f2087c98

6 files changed, 52 insertions, 8 deletions

diff --git a/media/base/media_switches.cc b/media/base/media_switches.cc
index 153c22a..70a958c 100644
--- a/media/base/media_switches.cc
+++ b/media/base/media_switches.cc
@@ -12,6 +12,9 @@ const char kAudioBufferSize[] = "audio-buffer-size";
 // Enable EAC3 playback in MSE.
 const char kEnableEac3Playback[] = "enable-eac3-playback";
 
+// Enables support for inband text tracks in media content.
+const char kEnableInbandTextTracks[] = "enable-inband-text-tracks";
+
 // Enables Opus playback in media elements.
 const char kEnableOpusPlayback[] = "enable-opus-playback";
 
diff --git a/media/base/media_switches.h b/media/base/media_switches.h
index 0462ada..590af80 100644
--- a/media/base/media_switches.h
+++ b/media/base/media_switches.h
@@ -16,6 +16,8 @@ MEDIA_EXPORT extern const char kAudioBufferSize[];
 
 MEDIA_EXPORT extern const char kEnableEac3Playback[];
 
+MEDIA_EXPORT extern const char kEnableInbandTextTracks[];
+
 MEDIA_EXPORT extern const char kEnableOpusPlayback[];
 
 MEDIA_EXPORT extern const char kEnableVp8AlphaPlayback[];
diff --git a/media/webm/webm_stream_parser.cc b/media/webm/webm_stream_parser.cc
index 27a01a8..828d318 100644
--- a/media/webm/webm_stream_parser.cc
+++ b/media/webm/webm_stream_parser.cc
@@ -177,7 +177,7 @@ int WebMStreamParser::ParseInfoAndTracks(const uint8* data, int size) {
   cur_size -= result;
   bytes_parsed += result;
 
-  WebMTracksParser tracks_parser(log_cb_);
+  WebMTracksParser tracks_parser(log_cb_, add_text_track_cb_.is_null());
   result = tracks_parser.Parse(cur, cur_size);
 
   if (result <= 0)
diff --git a/media/webm/webm_tracks_parser.cc b/media/webm/webm_tracks_parser.cc
index 93d0036..67bac04 100644
--- a/media/webm/webm_tracks_parser.cc
+++ b/media/webm/webm_tracks_parser.cc
@@ -28,11 +28,12 @@ static TextKind CodecIdToTextKind(const std::string& codec_id) {
   return kTextNone;
 }
 
-WebMTracksParser::WebMTracksParser(const LogCB& log_cb)
+WebMTracksParser::WebMTracksParser(const LogCB& log_cb, bool ignore_text_tracks)
     : track_type_(-1),
       track_num_(-1),
       audio_track_num_(-1),
       video_track_num_(-1),
+      ignore_text_tracks_(ignore_text_tracks),
       log_cb_(log_cb),
       audio_client_(log_cb),
       video_client_(log_cb) {
@@ -185,10 +186,15 @@ bool WebMTracksParser::OnListEnd(int id) {
       }
     } else if (track_type_ == kWebMTrackTypeSubtitlesOrCaptions ||
                track_type_ == kWebMTrackTypeDescriptionsOrMetadata) {
-      TextTrackInfo& text_track_info = text_tracks_[track_num_];
-      text_track_info.kind = text_track_kind;
-      text_track_info.name = track_name_;
-      text_track_info.language = track_language_;
+      if (ignore_text_tracks_) {
+        MEDIA_LOG(log_cb_) << "Ignoring text track " << track_num_;
+        ignored_tracks_.insert(track_num_);
+      } else {
+        TextTrackInfo& text_track_info = text_tracks_[track_num_];
+        text_track_info.kind = text_track_kind;
+        text_track_info.name = track_name_;
+        text_track_info.language = track_language_;
+      }
     } else {
       MEDIA_LOG(log_cb_) << "Unexpected TrackType " << track_type_;
       return false;
diff --git a/media/webm/webm_tracks_parser.h b/media/webm/webm_tracks_parser.h
index a7ec0e3..81588e4 100644
--- a/media/webm/webm_tracks_parser.h
+++ b/media/webm/webm_tracks_parser.h
@@ -26,7 +26,7 @@ namespace media {
 // Parser for WebM Tracks element.
 class MEDIA_EXPORT WebMTracksParser : public WebMParserClient {
  public:
-  explicit WebMTracksParser(const LogCB& log_cb);
+  explicit WebMTracksParser(const LogCB& log_cb, bool ignore_text_tracks);
   virtual ~WebMTracksParser();
 
   // Parses a WebM Tracks element in |buf|.
@@ -87,6 +87,7 @@ class MEDIA_EXPORT WebMTracksParser : public WebMParserClient {
 
   int64 audio_track_num_;
   int64 video_track_num_;
+  bool ignore_text_tracks_;
   TextTracks text_tracks_;
   std::set<int64> ignored_tracks_;
   std::string audio_encryption_key_id_;
diff --git a/media/webm/webm_tracks_parser_unittest.cc b/media/webm/webm_tracks_parser_unittest.cc
index 6d23669..a57d039 100644
--- a/media/webm/webm_tracks_parser_unittest.cc
+++ b/media/webm/webm_tracks_parser_unittest.cc
@@ -28,7 +28,7 @@ static void VerifyTextTrackInfo(const uint8* buffer,
                                 TextKind text_kind,
                                 const std::string& name,
                                 const std::string& language) {
-  scoped_ptr<WebMTracksParser> parser(new WebMTracksParser(LogCB()));
+  scoped_ptr<WebMTracksParser> parser(new WebMTracksParser(LogCB(), false));
 
   int result = parser->Parse(buffer, buffer_size);
   EXPECT_GT(result, 0);
@@ -90,4 +90,36 @@ TEST_F(WebMTracksParserTest, TestSubtitleYesNameYesLang) {
   VerifyTextTrackInfo(&buf[0], buf.size(), kTextSubtitles, "Picard", "fre");
 }
 
+TEST_F(WebMTracksParserTest, TestIgnoringTextTracks) {
+  InSequence s;
+
+  TracksBuilder tb;
+  tb.AddTrack(1, kWebMTrackTypeSubtitlesOrCaptions,
+              kWebMCodecSubtitles, "Subtitles", "fre");
+  tb.AddTrack(2, kWebMTrackTypeSubtitlesOrCaptions,
+              kWebMCodecSubtitles, "Commentary", "fre");
+
+  const std::vector<uint8> buf = tb.Finish();
+  scoped_ptr<WebMTracksParser> parser(new WebMTracksParser(LogCB(), true));
+
+  int result = parser->Parse(&buf[0], buf.size());
+  EXPECT_GT(result, 0);
+  EXPECT_EQ(result, static_cast<int>(buf.size()));
+
+  EXPECT_EQ(parser->text_tracks().size(), 0u);
+
+  const std::set<int64>& ignored_tracks = parser->ignored_tracks();
+  EXPECT_TRUE(ignored_tracks.find(1) != ignored_tracks.end());
+  EXPECT_TRUE(ignored_tracks.find(2) != ignored_tracks.end());
+
+  // Test again w/o ignoring the test tracks.
+  parser.reset(new WebMTracksParser(LogCB(), false));
+
+  result = parser->Parse(&buf[0], buf.size());
+  EXPECT_GT(result, 0);
+
+  EXPECT_EQ(parser->ignored_tracks().size(), 0u);
+  EXPECT_EQ(parser->text_tracks().size(), 2u);
+}
+
 }  // namespace media