media: Make MediaKeys ref-counted.

media/base/android/media_drm_bridge.cc

Index: media/base/android/media_drm_bridge.cc
diff --git a/media/base/android/media_drm_bridge.cc b/media/base/android/media_drm_bridge.cc
index d453ad921fb1e10bbb68552c69243af9c751d587..b23dd3e63d189ba9349d0eeda6de7f16d036c658 100644
--- a/media/base/android/media_drm_bridge.cc
+++ b/media/base/android/media_drm_bridge.cc
@@ -25,7 +25,6 @@
 #include "jni/MediaDrmBridge_jni.h"
 #include "media/base/android/media_client_android.h"
 #include "media/base/android/media_drm_bridge_delegate.h"
-#include "media/base/android/media_task_runner.h"
 #include "media/base/cdm_key_information.h"
 
 #include "widevine_cdm_version.h"  // In SHARED_INTERMEDIATE_DIR.
@@ -214,37 +213,6 @@ std::string GetSecurityLevelString(
 
 }  // namespace
 
-MediaDrmBridge::~MediaDrmBridge() {
-  DVLOG(1) << __FUNCTION__;
-
-  DCHECK(!use_media_thread_ || GetMediaTaskRunner()->BelongsToCurrentThread());
-
-  player_tracker_.NotifyCdmUnset();
-}
-
-void MediaDrmBridge::DeleteOnCorrectThread() {
-  DCHECK(task_runner_->BelongsToCurrentThread());
-  DVLOG(1) << __FUNCTION__;
-
-  JNIEnv* env = AttachCurrentThread();
-  if (!j_media_drm_.is_null())
-    Java_MediaDrmBridge_destroy(env, j_media_drm_.obj());
-
-  // After the call to Java_MediaDrmBridge_destroy() Java won't call native
-  // methods anymore, this is ensured by MediaDrmBridge.java.
-
-  // CdmPromiseAdapter must be destroyed on the UI thread.
-  cdm_promise_adapter_.reset();
-
-  // Post deletion onto Media thread if we use it.
-  if (use_media_thread_) {
-    weak_factory_.InvalidateWeakPtrs();
-    GetMediaTaskRunner()->DeleteSoon(FROM_HERE, this);
-  } else {
-    delete this;
-  }
-}
-
 // static
 bool MediaDrmBridge::IsAvailable() {
   if (base::android::BuildInfo::GetInstance()->sdk_int() < 19)
@@ -286,7 +254,7 @@ std::vector<std::string> MediaDrmBridge::GetPlatformKeySystemNames() {
 }
 
 // static
-ScopedMediaDrmBridgePtr MediaDrmBridge::Create(
+scoped_refptr<MediaDrmBridge> MediaDrmBridge::Create(
     const std::string& key_system,
     const SessionMessageCB& session_message_cb,
     const SessionClosedCB& session_closed_cb,
@@ -295,37 +263,32 @@ ScopedMediaDrmBridgePtr MediaDrmBridge::Create(
     const SessionExpirationUpdateCB& session_expiration_update_cb) {
   DVLOG(1) << __FUNCTION__;
 
-  scoped_ptr<MediaDrmBridge, BrowserCdmDeleter> media_drm_bridge;
   if (!IsAvailable())
-    return media_drm_bridge.Pass();
+    return nullptr;
 
   UUID scheme_uuid = g_key_system_manager.Get().GetUUID(key_system);
   if (scheme_uuid.empty())
-    return media_drm_bridge.Pass();
+    return nullptr;
 
-  media_drm_bridge.reset(
+  scoped_refptr<MediaDrmBridge> media_drm_bridge(
       new MediaDrmBridge(scheme_uuid, session_message_cb, session_closed_cb,
                          legacy_session_error_cb, session_keys_change_cb,
                          session_expiration_update_cb));
 
   if (media_drm_bridge->j_media_drm_.is_null())
-    media_drm_bridge.reset();
+    media_drm_bridge = nullptr;
 
-  return media_drm_bridge.Pass();
+  return media_drm_bridge;
 }
 
 // static
-ScopedMediaDrmBridgePtr MediaDrmBridge::CreateWithoutSessionSupport(
+scoped_refptr<MediaDrmBridge> MediaDrmBridge::CreateWithoutSessionSupport(
     const std::string& key_system) {
   return MediaDrmBridge::Create(
       key_system, SessionMessageCB(), SessionClosedCB(), LegacySessionErrorCB(),
       SessionKeysChangeCB(), SessionExpirationUpdateCB());
 }
 
-base::WeakPtr<MediaDrmBridge> MediaDrmBridge::WeakPtr() {
-  return weak_factory_.GetWeakPtr();
-}
-
 void MediaDrmBridge::SetServerCertificate(
     const std::vector<uint8_t>& certificate,
     scoped_ptr<media::SimpleCdmPromise> promise) {
@@ -452,14 +415,25 @@ CdmContext* MediaDrmBridge::GetCdmContext() {
   return nullptr;
 }
 
+void MediaDrmBridge::DeleteOnCorrectThread() const {
+  DVLOG(1) << __FUNCTION__;
+
+  if (!task_runner_->BelongsToCurrentThread()) {
+    // When DeleteSoon returns false, |this| will be leaked, which is okay.
+    task_runner_->DeleteSoon(FROM_HERE, this);
+  } else {
+    delete this;
+  }
+}
+
 int MediaDrmBridge::RegisterPlayer(const base::Closure& new_key_cb,
                                    const base::Closure& cdm_unset_cb) {
-  DCHECK(!use_media_thread_ || GetMediaTaskRunner()->BelongsToCurrentThread());
+  // |player_tracker_| can be accessed from any thread.
   return player_tracker_.RegisterPlayer(new_key_cb, cdm_unset_cb);
 }
 
 void MediaDrmBridge::UnregisterPlayer(int registration_id) {
-  DCHECK(!use_media_thread_ || GetMediaTaskRunner()->BelongsToCurrentThread());
+  // |player_tracker_| can be accessed from any thread.
   player_tracker_.UnregisterPlayer(registration_id);
 }
 
@@ -527,7 +501,14 @@ ScopedJavaLocalRef<jobject> MediaDrmBridge::GetMediaCrypto() {
 
 void MediaDrmBridge::SetMediaCryptoReadyCB(
     const MediaCryptoReadyCB& media_crypto_ready_cb) {
-  DCHECK(task_runner_->BelongsToCurrentThread());
+  if (!task_runner_->BelongsToCurrentThread()) {
+    task_runner_->PostTask(
+        FROM_HERE,
+        base::Bind(&MediaDrmBridge::SetMediaCryptoReadyCB,
+                   weak_factory_.GetWeakPtr(), media_crypto_ready_cb));
+    return;
+  }
+
   DVLOG(1) << __FUNCTION__;
 
   if (media_crypto_ready_cb.is_null()) {
@@ -558,25 +539,27 @@ void MediaDrmBridge::OnMediaCryptoReady(JNIEnv* env, jobject j_media_drm) {
     return;
 
   task_runner_->PostTask(
-      FROM_HERE, base::Bind(&MediaDrmBridge::NotifyMediaCryptoReady, WeakPtr(),
+      FROM_HERE, base::Bind(&MediaDrmBridge::NotifyMediaCryptoReady,
+                            weak_factory_.GetWeakPtr(),
                             base::ResetAndReturn(&media_crypto_ready_cb_)));
 }
 
 void MediaDrmBridge::OnPromiseResolved(JNIEnv* env,
                                        jobject j_media_drm,
                                        jint j_promise_id) {
-  task_runner_->PostTask(FROM_HERE, base::Bind(&MediaDrmBridge::ResolvePromise,
-                                               WeakPtr(), j_promise_id));
+  task_runner_->PostTask(FROM_HERE,
+                         base::Bind(&MediaDrmBridge::ResolvePromise,
+                                    weak_factory_.GetWeakPtr(), j_promise_id));
 }
 
 void MediaDrmBridge::OnPromiseResolvedWithSession(JNIEnv* env,
                                                   jobject j_media_drm,
                                                   jint j_promise_id,
                                                   jbyteArray j_session_id) {
-  task_runner_->PostTask(
-      FROM_HERE,
-      base::Bind(&MediaDrmBridge::ResolvePromiseWithSession, WeakPtr(),
-                 j_promise_id, GetSessionId(env, j_session_id)));
+  task_runner_->PostTask(FROM_HERE,
+                         base::Bind(&MediaDrmBridge::ResolvePromiseWithSession,
+                                    weak_factory_.GetWeakPtr(), j_promise_id,
+                                    GetSessionId(env, j_session_id)));
 }
 
 void MediaDrmBridge::OnPromiseRejected(JNIEnv* env,
@@ -585,8 +568,8 @@ void MediaDrmBridge::OnPromiseRejected(JNIEnv* env,
                                        jstring j_error_message) {
   task_runner_->PostTask(
       FROM_HERE,
-      base::Bind(&MediaDrmBridge::RejectPromise, WeakPtr(), j_promise_id,
-                 ConvertJavaStringToUTF8(env, j_error_message)));
+      base::Bind(&MediaDrmBridge::RejectPromise, weak_factory_.GetWeakPtr(),
+                 j_promise_id, ConvertJavaStringToUTF8(env, j_error_message)));
 }
 
 void MediaDrmBridge::OnSessionMessage(JNIEnv* env,
@@ -626,7 +609,7 @@ void MediaDrmBridge::OnSessionKeysChange(JNIEnv* env,
   DVLOG(2) << __FUNCTION__;
 
   if (has_additional_usable_key)
-    NotifyNewKeyOnCorrectThread();
+    player_tracker_.NotifyNewKey();
 
   CdmKeysInfo cdm_keys_info;
 
@@ -727,8 +710,6 @@ MediaDrmBridge::MediaDrmBridge(
       session_expiration_update_cb_(session_expiration_update_cb),
       cdm_promise_adapter_(new CdmPromiseAdapter()),
       task_runner_(base::ThreadTaskRunnerHandle::Get()),
-      use_media_thread_(UseMediaThreadForMediaPlayback()),
-      media_weak_factory_(this),
       weak_factory_(this) {
   DVLOG(1) << __FUNCTION__;
 
@@ -741,6 +722,20 @@ MediaDrmBridge::MediaDrmBridge(
       env, j_scheme_uuid.obj(), reinterpret_cast<intptr_t>(this)));
 }
 
+MediaDrmBridge::~MediaDrmBridge() {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+  DVLOG(1) << __FUNCTION__;
+
+  JNIEnv* env = AttachCurrentThread();
+
+  // After the call to Java_MediaDrmBridge_destroy() Java won't call native
+  // methods anymore, this is ensured by MediaDrmBridge.java.
+  if (!j_media_drm_.is_null())
+    Java_MediaDrmBridge_destroy(env, j_media_drm_.obj());
+
+  player_tracker_.NotifyCdmUnset();

[Tima Vaisburd, 2015/10/29 01:17:53]

There seem to be no players to notify, right? If you prefer to keep it here for
consistency, please explain it in the comment.

On the other hand, would it be possible to do the similar change in Cast and get
rid of NotifyCdmUnset() altogether?

[xhwang, 2015/10/29 03:12:31]

The fact that the callback won't fire is an implementation detail of the
MediaSourcePlayer and MediaCodecPlayer, who hold a scoped_refptr to the CDM and
know that these callbacks won't fire. However, it's possible that some other
player could hold a raw pointer to the CDM and will rely on this callback to
work properly. We don't have such a player now, but I'd like to keep
MediaDrmBridge self-contained.
We should. But I don't plan to dive too deep into ChromeCast code. ChromeCast
people can choose what to do next. If they do similar changes, we can drop
NotifyCdmUnset() altogther later.

+}
+
 // TODO(ddorwin): This is specific to Widevine. http://crbug.com/459400
 // static
 bool MediaDrmBridge::IsSecureDecoderRequired(SecurityLevel security_level) {
@@ -757,21 +752,6 @@ MediaDrmBridge::SecurityLevel MediaDrmBridge::GetSecurityLevel() {
   return GetSecurityLevelFromString(security_level_str);
 }
 
-void MediaDrmBridge::NotifyNewKeyOnCorrectThread() {
-  // Repost this method onto the Media thread if |use_media_thread_| is true.
-  if (use_media_thread_ && !GetMediaTaskRunner()->BelongsToCurrentThread()) {
-    GetMediaTaskRunner()->PostTask(
-        FROM_HERE, base::Bind(&MediaDrmBridge::NotifyNewKeyOnCorrectThread,
-                              media_weak_factory_.GetWeakPtr()));
-    return;
-  }
-
-  DCHECK(!use_media_thread_ || GetMediaTaskRunner()->BelongsToCurrentThread());
-  DVLOG(1) << __FUNCTION__;
-
-  player_tracker_.NotifyNewKey();
-}
-
 void MediaDrmBridge::NotifyMediaCryptoReady(const MediaCryptoReadyCB& cb) {
   DCHECK(task_runner_->BelongsToCurrentThread());