Enforce non-negative BitstreamBuffer id

content/common/gpu/media/video_decode_accelerator_unittest.cc

Index: content/common/gpu/media/video_decode_accelerator_unittest.cc
diff --git a/content/common/gpu/media/video_decode_accelerator_unittest.cc b/content/common/gpu/media/video_decode_accelerator_unittest.cc
index f325b40c8fcd317f72648a9fc05fdf9285775246..047365c47dbda662f58c75337130ebcd5e3d7442 100644
--- a/content/common/gpu/media/video_decode_accelerator_unittest.cc
+++ b/content/common/gpu/media/video_decode_accelerator_unittest.cc
@@ -603,7 +603,8 @@ void GLRenderingVDAClient::DecodeNextFragments() {
   base::SharedMemoryHandle dup_handle;
   CHECK(shm.ShareToProcess(base::Process::Current().handle(), &dup_handle));
   media::BitstreamBuffer bitstream_buffer(
-      next_bitstream_buffer_id_++, dup_handle, next_fragment_size);
+      next_bitstream_buffer_id_, dup_handle, next_fragment_size);
+  next_bitstream_buffer_id_ = (next_bitstream_buffer_id_ + 1) & 0x7FFFFFFF;

[Ami GONE FROM CHROMIUM, 2013/01/10 23:13:56]

This is kind of silly (since this is a unittest with controlled inputs) but to
be pedantic: your change relies on wrap-around overflow behavior (n_b_b_i_ is an
int) which is not what the standard gives you.
You could make n_b_b_i_ int64 (like GVD) or uint32 to make this snippet correct.

[sheu, 2013/01/10 23:34:48]

Fine.  :-)

   decoder_->Decode(bitstream_buffer);
   ++outstanding_decodes_;
   encoded_data_next_pos_to_decode_ = end_pos;