Adding VP8 Alpha support in Media Source

media/base/decoder_buffer.cc

Index: media/base/decoder_buffer.cc
diff --git a/media/base/decoder_buffer.cc b/media/base/decoder_buffer.cc
index aec45211f10d3d68998e304b445e463ea55b0f61..ad4e01665fc87e5255dc106c8070cda8ba8cbfaf 100644
--- a/media/base/decoder_buffer.cc
+++ b/media/base/decoder_buffer.cc
@@ -38,7 +38,8 @@ DecoderBuffer::DecoderBuffer(const uint8* data, int size,
 
   Initialize();
   memcpy(data_.get(), data, size_);
-  memcpy(side_data_.get(), side_data, side_data_size_);
+  if (side_data_size > 0)

[fgalligan1, 2013/05/21 00:02:43]

nit: Check side_data_size_

[vignesh, 2013/05/21 18:57:56]

Done.

+    memcpy(side_data_.get(), side_data, side_data_size_);

[acolwell GONE FROM CHROMIUM, 2013/05/21 17:14:11]

Why is this change needed? Are you seeing negative values passed in? If you are
worried about this, just put DCHECK_GE(side_data_size, 0); at the top of the
method.

[vignesh, 2013/05/21 18:57:56]

I made this change because i replaced the private constructor in
StreamParserBuffer to take side_data and side_data_size by default (the callers
will pass NULL if there is no side_data). So StreamParserBuffer always calls the
4 arg constructor of DecoderBuffer which gives rise to a possibility of
side_data_size being -1. This possibility didn't exist before. 

In fact, if StreamParserBuffer is the only class that inherits from
DecoderBuffer, we can actually go ahead and remove the 2 arg constructor (the
one without side_data) of DecoderBuffer and make the callers pass NULL if there
is no side_data there as well.

 }
 
 DecoderBuffer::~DecoderBuffer() {}