Add support for incremental cluster parsing.

media/filters/chunk_demuxer.cc

Index: media/filters/chunk_demuxer.cc
diff --git a/media/filters/chunk_demuxer.cc b/media/filters/chunk_demuxer.cc
index d437d9108d6b938fe2b51b27bc10a4ce1c8ff861..a1b6672d88d36e21878909e8155b932a41e762fb 100644
--- a/media/filters/chunk_demuxer.cc
+++ b/media/filters/chunk_demuxer.cc
@@ -130,7 +130,7 @@ void ChunkDemuxerStream::Flush() {
 bool ChunkDemuxerStream::CanAddBuffers(const BufferQueue& buffers) const {
   base::AutoLock auto_lock(lock_);
 
-  // If we haven't seen any buffers yet than anything can be added.
+  // If we haven't seen any buffers yet, then anything can be added.
   if (last_buffer_timestamp_ == kNoTimestamp)
     return true;
 
@@ -434,7 +434,7 @@ bool ChunkDemuxer::AppendData(const uint8* data, size_t length) {
     int cur_size = 0;
     int bytes_parsed = 0;
     int result = -1;
-    bool parsed_a_cluster = false;
+    bool can_complete_seek = false;
 
     byte_queue_.Peek(&cur, &cur_size);
 
@@ -449,16 +449,17 @@ bool ChunkDemuxer::AppendData(const uint8* data, size_t length) {
           }
           break;
 
-        case INITIALIZED:
-          result = ParseCluster_Locked(cur, cur_size);
+        case INITIALIZED: {
+          bool buffers_added = false;
+          result = ParseCluster_Locked(cur, cur_size, &buffers_added);
           if (result < 0) {
             VLOG(1) << "AppendData(): parsing data failed";
             ReportError_Locked(PIPELINE_ERROR_DECODE);
             return true;
           }
 
-          parsed_a_cluster = (result > 0);
-          break;
+          can_complete_seek |= (result > 0 && buffers_added);
+        } break;
 
         case WAITING_FOR_INIT:
         case ENDED:
@@ -477,7 +478,7 @@ bool ChunkDemuxer::AppendData(const uint8* data, size_t length) {
 
     byte_queue_.Pop(bytes_parsed);
 
-    if (parsed_a_cluster && seek_waits_for_data_) {
+    if (can_complete_seek && seek_waits_for_data_) {
       seek_waits_for_data_ = false;
 
       if (!seek_cb_.is_null())
@@ -730,49 +731,36 @@ bool ChunkDemuxer::SetupStreams() {
   return !no_supported_streams;
 }
 
-int ChunkDemuxer::ParseCluster_Locked(const uint8* data, int size) {
+int ChunkDemuxer::ParseCluster_Locked(const uint8* data, int size,
+                                      bool* buffers_added) {
   lock_.AssertAcquired();
   if (!cluster_parser_.get())
     return -1;
 
-  int id;
-  int64 element_size;
-  int result = WebMParseElementHeader(data, size, &id, &element_size);
-
-  if (result <= 0)
-    return result;
-
-  if (id == kWebMIdCues) {
-    if (size < (result + element_size)) {
-      // We don't have the whole element yet. Signal we need more data.
-      return 0;
-    }
-    // Skip the element.
-    return result + element_size;
-  } else if (id != kWebMIdCluster) {
-    VLOG(1) << "Unexpected ID 0x" << std::hex << id;
-    return -1;
-  }
-
   int bytes_parsed = cluster_parser_->Parse(data, size);
 
   if (bytes_parsed <= 0)
     return bytes_parsed;
 
-  // Make sure we can add the buffers to both streams before we actutally
-  // add them. This allows us to accept all of the data or none of it.
-  if ((audio_.get() &&
-       !audio_->CanAddBuffers(cluster_parser_->audio_buffers())) ||
-      (video_.get() &&
-       !video_->CanAddBuffers(cluster_parser_->video_buffers()))) {
-    return -1;
-  }
+  if (!cluster_parser_->audio_buffers().empty() ||
+      !cluster_parser_->video_buffers().empty()) {
+    // Make sure we can add the buffers to both streams before we actually
+    // add them. This allows us to accept all of the data or none of it.
+    if ((audio_.get() &&
+         !audio_->CanAddBuffers(cluster_parser_->audio_buffers())) ||
+        (video_.get() &&
+         !video_->CanAddBuffers(cluster_parser_->video_buffers()))) {
+      return -1;
+    }
 
-  if (audio_.get())
-    audio_->AddBuffers(cluster_parser_->audio_buffers());
+    if (audio_.get())
+      audio_->AddBuffers(cluster_parser_->audio_buffers());
 
-  if (video_.get())
-    video_->AddBuffers(cluster_parser_->video_buffers());
+    if (video_.get())
+      video_->AddBuffers(cluster_parser_->video_buffers());
+
+    *buffers_added = true;
+  }
 
   // TODO(acolwell) : make this more representative of what is actually
   // buffered.