LibWeb: Set decoder error when decoding fails

Userland/Libraries/LibWeb/HTML/AudioTrack.cpp

@@ -37,6 +37,10 @@ AudioTrack::AudioTrack(JS::Realm& realm, JS::NonnullGCPtr<HTMLMediaElement> medi
         auto playback_position = static_cast<double>(position.to_milliseconds()) / 1000.0;
         m_media_element->set_current_playback_position(playback_position);
     };
+
+    m_audio_plugin->on_decoder_error = [this](String error_message) {
+        m_media_element->set_decoder_error(error_message).release_value_but_fixme_should_propagate_errors();
+    };
 }
 
 AudioTrack::~AudioTrack()

Userland/Libraries/LibWeb/Platform/AudioCodecPlugin.h

@@ -35,6 +35,7 @@ public:
     virtual Duration duration() = 0;
 
     Function<void(Duration)> on_playback_position_updated;
+    Function<void(String)> on_decoder_error;
 
 protected:
     AudioCodecPlugin();

Userland/Libraries/LibWeb/Platform/AudioCodecPluginAgnostic.cpp

@@ -43,8 +43,17 @@ ErrorOr<NonnullOwnPtr<AudioCodecPluginAgnostic>> AudioCodecPluginAgnostic::creat
         Audio::OutputState::Suspended, loader->sample_rate(), /* channels = */ 2, latency_ms,
         [&plugin = *plugin, loader](Bytes buffer, Audio::PcmSampleFormat format, size_t sample_count) -> ReadonlyBytes {
             VERIFY(format == Audio::PcmSampleFormat::Float32);
-            auto samples = loader->get_more_samples(sample_count).release_value_but_fixme_should_propagate_errors();
+
+            auto samples_result = loader->get_more_samples(sample_count);
+
+            if (samples_result.is_error()) {
+                plugin.on_decoder_error(MUST(String::formatted("Decoding failure: {}", samples_result.error())));
+                return buffer.trim(0);
+            }
+
+            auto samples = samples_result.release_value();
             VERIFY(samples.size() <= sample_count);
+
             FixedMemoryStream writing_stream { buffer };
 
             for (auto& sample : samples) {