Avoid calling GetAllStreams() on uninitialized Demuxer

The first time we know the Demuxer initialization is complete is when
Pipeline::Start() completes (asynchronously).

Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
Change-Id: I7451187be2d141780d5aa514fb3a1ec4abe8fbbe
Reviewed-on: https://chromium-review.googlesource.com/1000858
Commit-Queue: Chrome Cunningham <chcunningham@chromium.org>
Reviewed-by: Chrome Cunningham <chcunningham@chromium.org>
Cr-Commit-Position: refs/heads/master@{#551156}

media/filters/chunk_demuxer_unittest.cc

@@ -1420,6 +1420,9 @@ TEST_P(ChunkDemuxerTest, Init) {
       EXPECT_FALSE(video_stream);
     }
 
+    for (auto* stream : demuxer_->GetAllStreams())
+      EXPECT_TRUE(stream->SupportsConfigChanges());
+
     ShutdownDemuxer();
     demuxer_.reset();
   }

media/filters/ffmpeg_demuxer_unittest.cc

@@ -517,6 +517,15 @@ TEST_F(FFmpegDemuxerTest, Initialize_Encrypted) {
   InitializeDemuxer();
 }
 
+TEST_F(FFmpegDemuxerTest, Initialize_NoConfigChangeSupport) {
+  // Will create one audio, one video, and one text stream.
+  CreateDemuxer("bear-vp8-webvtt.webm");
+  InitializeDemuxer();
+
+  for (auto* stream : demuxer_->GetAllStreams())
+    EXPECT_FALSE(stream->SupportsConfigChanges());
+}
+
 TEST_F(FFmpegDemuxerTest, AbortPendingReads) {
   // We test that on a successful audio packet read.
   CreateDemuxer("bear-320x240.webm");

media/test/pipeline_integration_test_base.cc

@@ -274,12 +274,11 @@ PipelineStatus PipelineIntegrationTestBase::StartInternal(
   // media files are provided in advance.
   EXPECT_CALL(*this, OnWaitingForDecryptionKey()).Times(0);
 
-  // SRC= demuxer does not support config changes.
-  for (auto* stream : demuxer_->GetAllStreams()) {
-    EXPECT_FALSE(stream->SupportsConfigChanges());
-  }
-  EXPECT_CALL(*this, OnAudioConfigChange(_)).Times(0);
-  EXPECT_CALL(*this, OnVideoConfigChange(_)).Times(0);
+  // DemuxerStreams may signal config changes.
+  // In practice, this doesn't happen for FFmpegDemuxer, but it's allowed for
+  // SRC= demuxers in general.
+  EXPECT_CALL(*this, OnAudioConfigChange(_)).Times(AnyNumber());
+  EXPECT_CALL(*this, OnVideoConfigChange(_)).Times(AnyNumber());
 
   base::RunLoop run_loop;
   pipeline_->Start(
@@ -606,10 +605,7 @@ PipelineStatus PipelineIntegrationTestBase::StartPipelineWithMediaSource(
                  base::Unretained(this), run_loop.QuitWhenIdleClosure()));
   demuxer_ = source->GetDemuxer();
 
-  // MediaSource demuxer may signal config changes.
-  for (auto* stream : demuxer_->GetAllStreams()) {
-    EXPECT_TRUE(stream->SupportsConfigChanges());
-  }
+  // DemuxerStreams may signal config changes.
   // Config change tests should set more specific expectations about the number
   // of calls.
   EXPECT_CALL(*this, OnAudioConfigChange(_)).Times(AnyNumber());
@@ -646,6 +642,10 @@ PipelineStatus PipelineIntegrationTestBase::StartPipelineWithMediaSource(
 
   RunUntilIdleOrEndedOrError(&run_loop);
 
+  for (auto* stream : demuxer_->GetAllStreams()) {
+    EXPECT_TRUE(stream->SupportsConfigChanges());
+  }
+
   return pipeline_status_;
 }