Pause EME player whose external surface is stolen by another player

content/browser/media/android/browser_media_player_manager.cc

Index: content/browser/media/android/browser_media_player_manager.cc
diff --git a/content/browser/media/android/browser_media_player_manager.cc b/content/browser/media/android/browser_media_player_manager.cc
index 752c2f19b550ce99d57ab1078df78aeeca515c68..61d9ab6a1fd46083f01340b6d4fe0f2bf01971bf 100644
--- a/content/browser/media/android/browser_media_player_manager.cc
+++ b/content/browser/media/android/browser_media_player_manager.cc
@@ -348,8 +348,15 @@ void BrowserMediaPlayerManager::AttachExternalVideoSurface(int player_id,
 
 void BrowserMediaPlayerManager::DetachExternalVideoSurface(int player_id) {
   MediaPlayerAndroid* player = GetPlayer(player_id);
-  if (player)
+  if (player) {
+    // If a player looses its external surface because
+    // it enters fullscreen, the video should not be paused.
+    if (player_id != fullscreen_player_id_) {
+      player->Release();
+      Send(new MediaPlayerMsg_DidMediaPlayerPause(RoutingID(), player_id));
+    }
     player->SetVideoSurface(gfx::ScopedJavaSurface());
+  }
 }
 
 void BrowserMediaPlayerManager::OnFrameInfoUpdated() {
@@ -394,8 +401,13 @@ void BrowserMediaPlayerManager::OnRequestExternalSurface(
 void BrowserMediaPlayerManager::OnEnterFullscreen(int player_id) {
   DCHECK_EQ(fullscreen_player_id_, -1);
 #if defined(VIDEO_HOLE)
+  fullscreen_player_id_ = player_id;

[qinmin, 2014/11/21 00:23:50]

As I mentioned earlier, using fullscreen_player_id to do the reentrance trick is
really bad. If another developer look at this code, he will see that
fullscreen_player_id is set to -1 on line 410, and will remove this line. And
that will break your logic.

Since there can be at most one player_id associated with
external_video_surface_container, can't we just do sth like
external_video_surface_container_->ReleaseCurrentExternalVideoSurfacePlayer()?

+  // Avoid Z-fight: when any player goes
+  // fullscreen release any external surface.
   if (external_video_surface_container_)
-    external_video_surface_container_->ReleaseExternalVideoSurface(player_id);
+    external_video_surface_container_->ReleaseExternalVideoSurface(
+        ExternalVideoSurfaceContainer::kAnyPlayer);
+  fullscreen_player_id_ = -1;
 #endif  // defined(VIDEO_HOLE)
   if (video_view_.get()) {
     fullscreen_player_id_ = player_id;