media: Always define |cdm_id| in CdmContext.

content/renderer/media/crypto/ppapi_decryptor.cc

Index: content/renderer/media/crypto/ppapi_decryptor.cc
diff --git a/content/renderer/media/crypto/ppapi_decryptor.cc b/content/renderer/media/crypto/ppapi_decryptor.cc
index bb5179f11932c80db21da6854353f0bc65b4fa3b..ba21ee184a1ceafce79b4ed5c960e6d7f2fd5ded 100644
--- a/content/renderer/media/crypto/ppapi_decryptor.cc
+++ b/content/renderer/media/crypto/ppapi_decryptor.cc
@@ -185,6 +185,10 @@ media::Decryptor* PpapiDecryptor::GetDecryptor() {
   return this;
 }
 
+int PpapiDecryptor::GetCdmId() const {
+  return kInvalidCdmId;

[ddorwin, 2015/01/05 22:59:05]

Should this be NOTREACHED()?

[xhwang, 2015/03/17 23:40:28]

Maybe, but that's very implementation dependent (e.g. the media pipeline always
call GetDecryptor() before GetCdmId()...). I think returning kInvalidCdmId is
more generic.

+}
+
 void PpapiDecryptor::RegisterNewKeyCB(StreamType stream_type,
                                       const NewKeyCB& new_key_cb) {
   if (!render_loop_proxy_->BelongsToCurrentThread()) {