Support for parsing encrypted WebM streams by src.

media/base/demuxer.h

Index: media/base/demuxer.h
diff --git a/media/base/demuxer.h b/media/base/demuxer.h
index 34150af00b3f9c9a433b7d886cbbed433a1a5b4f..e2f1962224caec94797a2deae47bd49bf4309c8c 100644
--- a/media/base/demuxer.h
+++ b/media/base/demuxer.h
@@ -64,6 +64,8 @@ class MEDIA_EXPORT Demuxer : public base::RefCountedThreadSafe<Demuxer> {
   // Returns the starting time for the media file.
   virtual base::TimeDelta GetStartTime() const = 0;
 
+  virtual void KeyAdded();

[ddorwin, 2012/08/22 23:20:29]

Comment.
Also, curious why this is needed now and wasn't before.

[fgalligan1, 2012/08/23 02:39:11]

I'm not sure I understand the question. Do you mean why did we not need this in
the first media source implementation? Because the javascript was controlling
when the encrypted data was passed in. And in the demo we didn't pass any data
until we gave media source the key. I'm guessing if the application didn't wait
the decoder would not have been happy.

[xhwang, 2012/08/23 19:04:53]

I removed the "waiting for key" part in the demo, so this is not necessary. If
the decryptor doesn't have a key when trying to decrypt an encrypted frame, the
media pipeline will wait until the key is added, or the pipeline is stopped.

In spec about this: section 5.1.9: Key Presense
The CL in chrome: http://codereview.chromium.org/10822026/

[fgalligan1, 2012/08/24 20:01:26]

Removed KeyAdded().

+
  protected:
   friend class base::RefCountedThreadSafe<Demuxer>;
   virtual ~Demuxer();