Move 'mdat' advancement logic to make more sense.

media/mp4/mp4_stream_parser.cc

Index: media/mp4/mp4_stream_parser.cc
diff --git a/media/mp4/mp4_stream_parser.cc b/media/mp4/mp4_stream_parser.cc
index 9d51959a3a32bbc8d45c0c4db8370c80e1093737..f5080df451a1fd80d53d3bac17d8db9e6a3035f4 100644
--- a/media/mp4/mp4_stream_parser.cc
+++ b/media/mp4/mp4_stream_parser.cc
@@ -80,11 +80,7 @@ bool MP4StreamParser::Parse(const uint8* buf, int size) {
 
   do {
     if (state_ == kParsingBoxes) {
-      if (mdat_tail_ > queue_.head()) {
-        result = queue_.Trim(mdat_tail_);
-      } else {
-        result = ParseBox(&err);
-      }
+      result = ParseBox(&err);
     } else {
       DCHECK_EQ(kEmittingSamples, state_);
       result = EnqueueSample(&audio_buffers, &video_buffers, &err);
@@ -322,6 +318,10 @@ bool MP4StreamParser::EnqueueSample(BufferQueue* audio_buffers,
     if (*err)
       return false;
 
+    // Remain in kEnqueueingSamples state, discarding data, until the end of
+    // the current 'mdat' box has been appended to the queue.
+    if (!queue_.Trim(mdat_tail_)) return false;

[acolwell GONE FROM CHROMIUM, 2012/07/30 15:45:50]

nit: Put return on its own line.

[strobe_, 2012/07/30 16:33:38]

Done.

+
     ChangeState(kParsingBoxes);
     end_of_segment_cb_.Run();
     return true;