Refactor MediaResource to be multi-stream capable

media/test/pipeline_integration_test.cc

Index: media/test/pipeline_integration_test.cc
diff --git a/media/test/pipeline_integration_test.cc b/media/test/pipeline_integration_test.cc
index 8d103107a0cc54b5c59ee3b03f589f45ad4532c8..8b44eb7f26bb06fea2b6444bcd6c84276ab5aed9 100644
--- a/media/test/pipeline_integration_test.cc
+++ b/media/test/pipeline_integration_test.cc
@@ -1180,8 +1180,8 @@ TEST_F(PipelineIntegrationTest,
        MAYBE_CLOCKLESS(BasicPlaybackOpusPrerollExceedsCodecDelay)) {
   ASSERT_EQ(PIPELINE_OK, Start("bear-opus.webm", kHashed | kClockless));
 
-  AudioDecoderConfig config =
-      demuxer_->GetStream(DemuxerStream::AUDIO)->audio_decoder_config();
+  EXPECT_EQ(1u, demuxer_->GetStreams().size());
+  AudioDecoderConfig config = demuxer_->GetStreams()[0]->audio_decoder_config();
 
   // Verify that this file's preroll is not eclipsed by the codec delay so we
   // can detect when preroll is not properly performed.
@@ -1208,8 +1208,8 @@ TEST_F(PipelineIntegrationTest,
                              &source, kClockless | kHashed, nullptr));
   source.EndOfStream();
 
-  AudioDecoderConfig config =
-      demuxer_->GetStream(DemuxerStream::AUDIO)->audio_decoder_config();
+  EXPECT_EQ(1u, demuxer_->GetStreams().size());
+  AudioDecoderConfig config = demuxer_->GetStreams()[0]->audio_decoder_config();
 
   // Verify that this file's preroll is not eclipsed by the codec delay so we
   // can detect when preroll is not properly performed.
@@ -2524,9 +2524,11 @@ TEST_F(PipelineIntegrationTest, BasicPlayback_Opus441kHz) {
   ASSERT_EQ(PIPELINE_OK, Start("sfx-opus-441.webm"));
   Play();
   ASSERT_TRUE(WaitUntilOnEnded());
-  EXPECT_EQ(48000, demuxer_->GetStream(DemuxerStream::AUDIO)
-                       ->audio_decoder_config()
-                       .samples_per_second());
+
+  EXPECT_EQ(1u, demuxer_->GetStreams().size());
+  EXPECT_EQ(
+      48000,
+      demuxer_->GetStreams()[0]->audio_decoder_config().samples_per_second());
 }
 
 // Same as above but using MediaSource.
@@ -2539,9 +2541,10 @@ TEST_F(PipelineIntegrationTest, BasicPlayback_MediaSource_Opus441kHz) {
   ASSERT_TRUE(WaitUntilOnEnded());
   source.Shutdown();
   Stop();
-  EXPECT_EQ(48000, demuxer_->GetStream(DemuxerStream::AUDIO)
-                       ->audio_decoder_config()
-                       .samples_per_second());
+  EXPECT_EQ(1u, demuxer_->GetStreams().size());
+  EXPECT_EQ(
+      48000,
+      demuxer_->GetStreams()[0]->audio_decoder_config().samples_per_second());
 }
 
 // Ensures audio-only playback with missing or negative timestamps works.  Tests