Encrypted Media: Implement IPC based SetCdm().

content/renderer/media/android/webmediaplayer_android.cc

Index: content/renderer/media/android/webmediaplayer_android.cc
diff --git a/content/renderer/media/android/webmediaplayer_android.cc b/content/renderer/media/android/webmediaplayer_android.cc
index b59ddbba967ba7131e63012ca407f452db4fa71a..d8f9503d723fbbf69545db2eb1f071762853bf68 100644
--- a/content/renderer/media/android/webmediaplayer_android.cc
+++ b/content/renderer/media/android/webmediaplayer_android.cc
@@ -18,10 +18,10 @@
 #include "cc/layers/video_layer.h"
 #include "content/public/common/content_client.h"
 #include "content/public/renderer/render_frame.h"
-#include "content/renderer/media/android/proxy_media_keys.h"
 #include "content/renderer/media/android/renderer_demuxer_android.h"
 #include "content/renderer/media/android/renderer_media_player_manager.h"
 #include "content/renderer/media/crypto/key_systems.h"
+#include "content/renderer/media/webcontentdecryptionmodule_impl.h"
 #include "content/renderer/media/webmediaplayer_delegate.h"
 #include "content/renderer/media/webmediaplayer_util.h"
 #include "content/renderer/render_frame_impl.h"
@@ -31,6 +31,8 @@
 #include "gpu/command_buffer/common/mailbox_holder.h"
 #include "media/base/android/media_player_android.h"
 #include "media/base/bind_to_current_loop.h"
+// TODO(xhwang): Remove when we remove prefixed EME implementation.
+#include "media/base/media_keys.h"
 #include "media/base/media_switches.h"
 #include "media/base/video_frame.h"
 #include "net/base/mime_util.h"
@@ -106,6 +108,7 @@ WebMediaPlayerAndroid::WebMediaPlayerAndroid(
       current_time_(0),
       is_remote_(false),
       media_log_(media_log),
+      web_cdm_(NULL),
       weak_factory_(this) {
   DCHECK(manager_);
 
@@ -1247,8 +1250,6 @@ WebMediaPlayerAndroid::GenerateKeyRequestInternal(
           frame_,
 #else
           manager_,
-          player_id_,  // TODO(xhwang): Use cdm_id when MediaKeys are
-                       // separated from WebMediaPlayer.
 #endif  // defined(ENABLE_PEPPER_CDMS)
           base::Bind(&WebMediaPlayerAndroid::OnKeyAdded,
                      weak_factory_.GetWeakPtr()),
@@ -1263,11 +1264,12 @@ WebMediaPlayerAndroid::GenerateKeyRequestInternal(
       return WebMediaPlayer::MediaKeyExceptionKeySystemNotSupported;
     }
 
-    if (proxy_decryptor_ && !decryptor_ready_cb_.is_null()) {
+    if (!decryptor_ready_cb_.is_null()) {
       base::ResetAndReturn(&decryptor_ready_cb_)
           .Run(proxy_decryptor_->GetDecryptor());
     }
 
+    manager_->SetCdm(player_id_, proxy_decryptor_->GetCdmId());

[ddorwin, 2014/03/25 23:03:59]

As mentioned before, It seems odd that we make this call even in the Clear Key
case. Maybe ProxyDecryptor should somehow abstract this. (Probably not worth
doing since this will all be deleted.)

[xhwang, 2014/03/26 06:02:04]

As mentioned earlier, if we check GetCdmId() before calling SetCdm(), we can
avoid supporting kIncalidCdmId in RenderMediaPlayerManager, that would prevent
us from calling SetCdm() for Clear Key (because AesDecryptor doesn't have a
valid cdm ID). WDYT of that?

For abstraction/clean-up, I'd like to do that later because:
1, A lot of these code will go away.
2, We may want to implement Clear Key in the browser side.
3, We may want to merge WMPI and WMPA.
All of these make me feel we need some larger scale refactoring than small
clean-up in WMPA.

[ddorwin, 2014/03/26 19:25:59]

Does this mean we'd move kInvalidCdmId up the stack?
Another option would be to provide an ID for all CDMs. That would probably need
to be Android-specific code in CDMFactory. While it might add more ifdefs in its
files, at least it might contain it.

It seems that either of these would allow us to DCHECK on 0 until we implement
support for setMediaKeys(0).
Are you saying we shouldn't do what you said in the first paragraph because we
want to clean these up?

[xhwang, 2014/03/27 19:07:42]

Added TODO in RMPM.

     current_key_system_ = key_system;
   } else if (key_system != current_key_system_) {
     return WebMediaPlayer::MediaKeyExceptionInvalidPlayerState;
@@ -1367,6 +1369,22 @@ WebMediaPlayerAndroid::CancelKeyRequestInternal(const std::string& key_system,
   return WebMediaPlayer::MediaKeyExceptionNoError;
 }
 
+void WebMediaPlayerAndroid::setContentDecryptionModule(
+    blink::WebContentDecryptionModule* cdm) {

[ddorwin, 2014/03/25 23:03:59]

Why was DCHECK(main_loop_->BelongsToCurrentThread()); from PS1 removed?

[xhwang, 2014/03/26 06:02:04]

Because main_loop_ doesn't exist any more after rebase. Fixed now.

+  // TODO(xhwang): Support setMediaKeys(0) if necessary: http://crbug.com/330324
+  if (!cdm)
+    return;
+
+  web_cdm_ = ToWebContentDecryptionModuleImpl(cdm);
+  if (!web_cdm_)
+    return;
+
+  if (!decryptor_ready_cb_.is_null())
+    base::ResetAndReturn(&decryptor_ready_cb_).Run(web_cdm_->GetDecryptor());
+
+  manager_->SetCdm(player_id_, web_cdm_->GetCdmId());

[ddorwin, 2014/03/25 23:03:59]

Ditto from l1272, though we don't have an abstraction here. Hmm. maybe we need a
way for CK to say this CDM ID is handled in the renderer.

[xhwang, 2014/03/26 06:02:04]

For Clear Key, GetCdmId is kInvalidCdmId and hence this call does nothing.

+}
+
 void WebMediaPlayerAndroid::OnKeyAdded(const std::string& session_id) {
   EmeUMAHistogramCounts(current_key_system_, "KeyAdded", 1);
 
@@ -1455,13 +1473,18 @@ void WebMediaPlayerAndroid::SetDecryptorReadyCB(
   // detail.
   DCHECK(decryptor_ready_cb_.is_null());
 
+  // Mixed use of prefixed and unprefixed EME APIs is disallowed by Blink.
+  DCHECK(!proxy_decryptor_ || !web_cdm_);
+
   if (proxy_decryptor_) {
     decryptor_ready_cb.Run(proxy_decryptor_->GetDecryptor());
     return;
   }
 
-  // TODO(xhwang): Also notify |web_cdm_| when we implement
-  // setContentDecryptionModule(). See: http://crbug.com/224786
+  if (web_cdm_) {
+    decryptor_ready_cb.Run(web_cdm_->GetDecryptor());
+    return;
+  }
 
   decryptor_ready_cb_ = decryptor_ready_cb;
 }