Implement experimental MP3 support for Media Source API.

media/base/media_log.h

Index: media/base/media_log.h
diff --git a/media/base/media_log.h b/media/base/media_log.h
index 1d25c0973a5dfc865712e1d7fe3c075e4cba6b2a..049630edba2d08f7dddebe3180204174e3d0732d 100644
--- a/media/base/media_log.h
+++ b/media/base/media_log.h
@@ -22,7 +22,7 @@ namespace media {
 typedef base::Callback<void(const std::string&)> LogCB;
 
 // Helper class to make it easier to use log_cb like DVLOG().
-class LogHelper {
+class MEDIA_EXPORT LogHelper {

[scherkus (not reviewing), 2013/09/03 19:34:22]

is this change needed? I don't see any new references to LogHelper outside of
the media target in this CL

[acolwell GONE FROM CHROMIUM, 2013/09/04 00:48:13]

Nope. This was only needed when I was doing some debugging in
PipelineIntegration test.

  public:
   LogHelper(const LogCB& Log_cb);
   ~LogHelper();