Fix various MediaSource related crashes on Android.

This change fixes several issues that were causing crashes.
- MediaPlayerHostMsg_DemuxerReady_Params was not initializing the xxx_codec
member variables so audio-only or video-only content would randomly be
flagged as A/V content with a random codec ID.
- ChunkDemuxer::Stop() was not being called which could cause the delegate
to be accessed after it was destroyed.
- MediaSourceDelegate was signalling that it had metadata before the 
ChunkDemuxer was even initialized. This caused the HTMLMediaElement to
signal that the load completed way too early and caused play() to be
called when the delegate wasn't ready.

BUG=233420
TEST=webkitmediasource-play.html LayoutTest reliably runs w/o crashing now.

Review URL: https://chromiumcodereview.appspot.com/15898002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@202019 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 8 insertions, 5 deletions

diff --git a/media/base/android/demuxer_stream_player_params.cc b/media/base/android/demuxer_stream_player_params.cc
index ab9fcaf..3ed1a8c 100644
--- a/media/base/android/demuxer_stream_player_params.cc
+++ b/media/base/android/demuxer_stream_player_params.cc
@@ -8,9 +8,11 @@ namespace media {
 
 MediaPlayerHostMsg_DemuxerReady_Params::
     MediaPlayerHostMsg_DemuxerReady_Params()
-    : audio_channels(0),
+    : audio_codec(kUnknownAudioCodec),
+      audio_channels(0),
       audio_sampling_rate(0),
       is_audio_encrypted(false),
+      video_codec(kUnknownVideoCodec),
       is_video_encrypted(false),
       duration_ms(0) {}
 
diff --git a/media/base/android/media_source_player.cc b/media/base/android/media_source_player.cc
index b29d182..f6cbd48 100644
--- a/media/base/android/media_source_player.cc
+++ b/media/base/android/media_source_player.cc
@@ -208,7 +208,6 @@ MediaSourcePlayer::MediaSourcePlayer(
       waiting_for_audio_data_(false),
       waiting_for_video_data_(false),
       weak_this_(this) {
-  OnMediaMetadataChanged(duration_, width_, height_, false);
 }
 
 MediaSourcePlayer::~MediaSourcePlayer() {
@@ -221,9 +220,11 @@ void MediaSourcePlayer::SetVideoSurface(jobject surface) {
     return;
   }
 
-  video_decoder_job_.reset(new VideoDecoderJob(
-      base::MessageLoopProxy::current(), video_codec_,
-      gfx::Size(width_, height_), surface));
+  if (HasVideo()) {
+    video_decoder_job_.reset(new VideoDecoderJob(
+        base::MessageLoopProxy::current(), video_codec_,
+        gfx::Size(width_, height_), surface));
+  }
 
   if (pending_play_)
     StartInternal();