Simplify AudioSplicer logic which slots buffers before or after a splice point.

media/filters/decoder_stream.cc

Index: media/filters/decoder_stream.cc
diff --git a/media/filters/decoder_stream.cc b/media/filters/decoder_stream.cc
index 350e47f72cd3887c2fd01ee9d878774791254745..c4adc632ba89a897cbc222bae14e3737ff3f93df 100644
--- a/media/filters/decoder_stream.cc
+++ b/media/filters/decoder_stream.cc
@@ -50,6 +50,7 @@ DecoderStream<StreamType>::DecoderStream(
           new DecoderSelector<StreamType>(task_runner,
                                           decoders.Pass(),
                                           set_decryptor_ready_cb)),
+      active_splice_(false),
       weak_factory_(this) {}
 
 template <DemuxerStream::Type StreamType>
@@ -408,9 +409,12 @@ void DecoderStream<StreamType>::OnBufferReady(
     return;
   }
 
-  if (!splice_observer_cb_.is_null() && !buffer->end_of_stream() &&
-      buffer->splice_timestamp() != kNoTimestamp()) {
-    splice_observer_cb_.Run(buffer->splice_timestamp());
+  if (!splice_observer_cb_.is_null() && !buffer->end_of_stream()) {
+    const bool has_splice_ts = buffer->splice_timestamp() != kNoTimestamp();
+    if (active_splice_ || has_splice_ts) {
+      splice_observer_cb_.Run(buffer->splice_timestamp());
+      active_splice_ = has_splice_ts;
+    }
   }
 
   DCHECK(status == DemuxerStream::kOk) << status;