Revert of Fix a crash that MediaPlayerAndroid weak_ptr is incorrectly used...

Revert of Fix a crash that MediaPlayerAndroid weak_ptr is incorrectly used across thread (patchset #1 id:1 of https://codereview.chromium.org/899473002/)

Reason for revert:
this CL doesn't fix the original issue

Original issue's description:
> Fix a crash that MediaPlayerAndroid weak_ptr is incorrectly used across thread
>
> For MediaPlayerListener, the callbacks can happen on a non-UI thread.
> Weak_ptr is not thread safe, so we shouldn't bind the weak_ptr in those callbacks.
> This change creates a threadsafe proxy class to bridge all the callbacks.
>
> BUG=453581, 447368, 447367
>
> Committed: https://crrev.com/2e9885788692f69203a98fb42347428ef553d640
> Cr-Commit-Position: refs/heads/master@{#314241}

TBR=xhwang@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=453581, 447368, 447367

Review URL: https://codereview.chromium.org/879273006

Cr-Commit-Position: refs/heads/master@{#315352}

media/base/android/media_player_android.h

@@ -75,6 +75,16 @@ class MEDIA_EXPORT MediaPlayerAndroid {
   // Associates the |cdm| with this player.
   virtual void SetCdm(BrowserCdm* cdm);
 
+  int player_id() { return player_id_; }
+
+  GURL frame_url() { return frame_url_; }
+
+ protected:
+  MediaPlayerAndroid(int player_id,
+                     MediaPlayerManager* manager,
+                     const RequestMediaResourcesCB& request_media_resources_cb,
+                     const GURL& frame_url);
+
   // TODO(qinmin): Simplify the MediaPlayerListener class to only listen to
   // media interrupt events. And have a separate child class to listen to all
   // the events needed by MediaPlayerBridge. http://crbug.com/422597.
@@ -87,16 +97,6 @@ class MEDIA_EXPORT MediaPlayerAndroid {
   virtual void OnSeekComplete();
   virtual void OnMediaPrepared();
 
-  int player_id() { return player_id_; }
-
-  GURL frame_url() { return frame_url_; }
-
- protected:
-  MediaPlayerAndroid(int player_id,
-                     MediaPlayerManager* manager,
-                     const RequestMediaResourcesCB& request_media_resources_cb,
-                     const GURL& frame_url);
-
   // Attach/Detaches |listener_| for listening to all the media events. If
   // |j_media_player| is NULL, |listener_| only listens to the system media
   // events. Otherwise, it also listens to the events from |j_media_player|.
@@ -108,6 +108,8 @@ class MEDIA_EXPORT MediaPlayerAndroid {
   RequestMediaResourcesCB request_media_resources_cb_;
 
  private:
+  friend class MediaPlayerListener;
+
   // Player ID assigned to this player.
   int player_id_;
 

media/base/android/media_player_listener.cc

@@ -18,7 +18,7 @@ using base::android::ScopedJavaLocalRef;
 
 namespace media {
 
-MediaPlayerListenerProxy::MediaPlayerListenerProxy(
+MediaPlayerListener::MediaPlayerListener(
     const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
     base::WeakPtr<MediaPlayerAndroid> media_player)
     : task_runner_(task_runner),
@@ -27,100 +27,6 @@ MediaPlayerListenerProxy::MediaPlayerListenerProxy(
   DCHECK(media_player_);
 }
 
-void MediaPlayerListenerProxy::OnMediaError(int error_type) {
-  if (!task_runner_->BelongsToCurrentThread()) {
-    task_runner_->PostTask(
-        FROM_HERE,
-        base::Bind(&MediaPlayerListenerProxy::OnMediaError, this, error_type));
-    return;
-  }
-
-  if (media_player_)
-    media_player_->OnMediaError(error_type);
-}
-
-void MediaPlayerListenerProxy::OnVideoSizeChanged(int width, int height) {
-  if (!task_runner_->BelongsToCurrentThread()) {
-    task_runner_->PostTask(
-        FROM_HERE,
-        base::Bind(&MediaPlayerListenerProxy::OnVideoSizeChanged,
-                   this, width, height));
-    return;
-  }
-
-  if (media_player_)
-    media_player_->OnVideoSizeChanged(width, height);
-}
-
-void MediaPlayerListenerProxy::OnBufferingUpdate(int percent) {
-  if (!task_runner_->BelongsToCurrentThread()) {
-    task_runner_->PostTask(
-        FROM_HERE,
-        base::Bind(&MediaPlayerListenerProxy::OnBufferingUpdate,
-                   this, percent));
-    return;
-  }
-
-  if (media_player_)
-    media_player_->OnBufferingUpdate(percent);
-}
-
-void MediaPlayerListenerProxy::OnPlaybackComplete() {
-  if (!task_runner_->BelongsToCurrentThread()) {
-    task_runner_->PostTask(
-        FROM_HERE,
-        base::Bind(&MediaPlayerListenerProxy::OnPlaybackComplete, this));
-    return;
-  }
-
-  if (media_player_)
-    media_player_->OnPlaybackComplete();
-}
-
-void MediaPlayerListenerProxy::OnSeekComplete() {
-  if (!task_runner_->BelongsToCurrentThread()) {
-    task_runner_->PostTask(
-        FROM_HERE,
-        base::Bind(&MediaPlayerListenerProxy::OnSeekComplete, this));
-    return;
-  }
-
-  if (media_player_)
-    media_player_->OnSeekComplete();
-}
-
-void MediaPlayerListenerProxy::OnMediaPrepared() {
-  if (!task_runner_->BelongsToCurrentThread()) {
-    task_runner_->PostTask(
-        FROM_HERE,
-        base::Bind(&MediaPlayerListenerProxy::OnMediaPrepared, this));
-    return;
-  }
-
-  if (media_player_)
-    media_player_->OnMediaPrepared();
-}
-
-void MediaPlayerListenerProxy::OnMediaInterrupted() {
-  if (!task_runner_->BelongsToCurrentThread()) {
-    task_runner_->PostTask(
-        FROM_HERE,
-        base::Bind(&MediaPlayerListenerProxy::OnMediaInterrupted, this));
-    return;
-  }
-
-  if (media_player_)
-    media_player_->OnMediaInterrupted();
-}
-
-MediaPlayerListenerProxy::~MediaPlayerListenerProxy() {}
-
-MediaPlayerListener::MediaPlayerListener(
-    const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
-    base::WeakPtr<MediaPlayerAndroid> media_player)
-    : proxy_(new MediaPlayerListenerProxy(task_runner, media_player)) {
-}
-
 MediaPlayerListener::~MediaPlayerListener() {}
 
 void MediaPlayerListener::CreateMediaPlayerListener(
@@ -133,6 +39,7 @@ void MediaPlayerListener::CreateMediaPlayerListener(
   }
 }
 
+
 void MediaPlayerListener::ReleaseMediaPlayerListenerResources() {
   JNIEnv* env = AttachCurrentThread();
   CHECK(env);
@@ -145,37 +52,45 @@ void MediaPlayerListener::ReleaseMediaPlayerListenerResources() {
 
 void MediaPlayerListener::OnMediaError(
     JNIEnv* /* env */, jobject /* obj */, jint error_type) {
-  proxy_->OnMediaError(error_type);
+  task_runner_->PostTask(FROM_HERE, base::Bind(
+      &MediaPlayerAndroid::OnMediaError, media_player_, error_type));
 }
 
 void MediaPlayerListener::OnVideoSizeChanged(
     JNIEnv* /* env */, jobject /* obj */, jint width, jint height) {
-  proxy_->OnVideoSizeChanged(width, height);
+  task_runner_->PostTask(FROM_HERE, base::Bind(
+      &MediaPlayerAndroid::OnVideoSizeChanged, media_player_,
+      width, height));
 }
 
 void MediaPlayerListener::OnBufferingUpdate(
     JNIEnv* /* env */, jobject /* obj */, jint percent) {
-  proxy_->OnBufferingUpdate(percent);
+  task_runner_->PostTask(FROM_HERE, base::Bind(
+      &MediaPlayerAndroid::OnBufferingUpdate, media_player_, percent));
 }
 
 void MediaPlayerListener::OnPlaybackComplete(
     JNIEnv* /* env */, jobject /* obj */) {
-  proxy_->OnPlaybackComplete();
+  task_runner_->PostTask(FROM_HERE, base::Bind(
+      &MediaPlayerAndroid::OnPlaybackComplete, media_player_));
 }
 
 void MediaPlayerListener::OnSeekComplete(
     JNIEnv* /* env */, jobject /* obj */) {
-  proxy_->OnSeekComplete();
+  task_runner_->PostTask(FROM_HERE, base::Bind(
+      &MediaPlayerAndroid::OnSeekComplete, media_player_));
 }
 
 void MediaPlayerListener::OnMediaPrepared(
     JNIEnv* /* env */, jobject /* obj */) {
-  proxy_->OnMediaPrepared();
+  task_runner_->PostTask(FROM_HERE, base::Bind(
+      &MediaPlayerAndroid::OnMediaPrepared, media_player_));
 }
 
 void MediaPlayerListener::OnMediaInterrupted(
     JNIEnv* /* env */, jobject /* obj */) {
-  proxy_->OnMediaInterrupted();
+  task_runner_->PostTask(FROM_HERE, base::Bind(
+      &MediaPlayerAndroid::OnMediaInterrupted, media_player_));
 }
 
 bool MediaPlayerListener::RegisterMediaPlayerListener(JNIEnv* env) {

media/base/android/media_player_listener.h

@@ -19,32 +19,6 @@ namespace media {
 
 class MediaPlayerAndroid;
 
-// Helper class for posting MediaPlayerAndroid tasks on the UI thread.
-class MediaPlayerListenerProxy
-    : public base::RefCountedThreadSafe<MediaPlayerListenerProxy> {
- public:
-  MediaPlayerListenerProxy(
-      const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
-      base::WeakPtr<MediaPlayerAndroid> media_player);
-  void OnMediaError(int error_type);
-  void OnVideoSizeChanged(int width, int height);
-  void OnBufferingUpdate(int percent);
-  void OnPlaybackComplete();
-  void OnSeekComplete();
-  void OnMediaPrepared();
-  void OnMediaInterrupted();
-
- private:
-  friend class base::RefCountedThreadSafe<MediaPlayerListenerProxy>;
-  ~MediaPlayerListenerProxy();
-
-  // The message loop where |media_player_| lives.
-  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
-
-  // The MediaPlayerAndroid object all the callbacks should be sent to.
-  base::WeakPtr<MediaPlayerAndroid> media_player_;
-};
-
 // Acts as a thread proxy between java MediaPlayerListener object and
 // MediaPlayerAndroid so that callbacks are posted onto the UI thread.
 class MediaPlayerListener {
@@ -55,7 +29,7 @@ class MediaPlayerListener {
   MediaPlayerListener(
       const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
       base::WeakPtr<MediaPlayerAndroid> media_player);
-  virtual ~MediaPlayerListener();
+ virtual ~MediaPlayerListener();
 
   // Called by the Java MediaPlayerListener and mirrored to corresponding
   // callbacks.
@@ -78,8 +52,11 @@ class MediaPlayerListener {
   static bool RegisterMediaPlayerListener(JNIEnv* env);
 
  private:
-  // Proxy for posting tasks to the UI thread.
-  scoped_refptr<MediaPlayerListenerProxy> proxy_;
+  // The message loop where |media_player_| lives.
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
+
+  // The MediaPlayerAndroid object all the callbacks should be sent to.
+  base::WeakPtr<MediaPlayerAndroid> media_player_;
 
   base::android::ScopedJavaGlobalRef<jobject> j_media_player_listener_;