Pause EME player whose external surface is stolen by another player

android_webview/java/src/org/chromium/android_webview/ExternalVideoSurfaceContainer.java

Index: android_webview/java/src/org/chromium/android_webview/ExternalVideoSurfaceContainer.java
diff --git a/android_webview/java/src/org/chromium/android_webview/ExternalVideoSurfaceContainer.java b/android_webview/java/src/org/chromium/android_webview/ExternalVideoSurfaceContainer.java
index e0e1f6657bf19d9a7d1826b210ce17cb8a36e9c5..6a8f73026b2a2122947f293f6da652d2558d79d6 100644
--- a/android_webview/java/src/org/chromium/android_webview/ExternalVideoSurfaceContainer.java
+++ b/android_webview/java/src/org/chromium/android_webview/ExternalVideoSurfaceContainer.java
@@ -127,6 +127,14 @@ public class ExternalVideoSurfaceContainer implements SurfaceHolder.Callback {
     }
 
     /**
+     * Returns id of player currently using the external video surface.
+     */
+    @CalledByNative
+    protected int getCurrentPlayerId() {
+        return mPlayerId;

[boliu, 2014/12/04 23:33:26]

Is it safe to assert mPlayerId != INVALID_PLAYER_ID here? Maybe there is already
a copy of INVALID_PLAYER_ID somewhere in native code?

I'm concerned that the implementation in content/ is making assumptions about
the value of a constant defined in android_webview/

[Hugo Holgersson, 2014/12/08 16:41:08]

My idea is that getCurrentPlayerId() should return mPlayerId, even if it is
INVALID_PLAYER_ID or something else. The user,
ReleasePlayerOfExternalVideoSurfaceIfNeeded(), interpretates if the value is
sane or not.
The value of the constant, INVALID_PLAYER_ID in android_webview, should not
matter to content. The first player has id 0 because RendererMediaPlayerManager
starts with next_media_player_id_(0).
ReleasePlayerOfExternalVideoSurfaceIfNeeded() depends on this convention: if a
player id is smaller than zero, it is not a valid player id so
ReleasePlayerOfExternalVideoSurfaceIfNeeded() has nothing to do.

[boliu, 2014/12/08 17:51:47]

You just outlined exactly how content code depends on INVALID_PLAYER_ID

+    }
+
+    /**
      * Called when a media player wants to release an external video surface.
      * @param playerId The ID of the media player.
      */
@@ -139,6 +147,9 @@ public class ExternalVideoSurfaceContainer implements SurfaceHolder.Callback {
         mPlayerId = INVALID_PLAYER_ID;
     }
 
+    /**
+     * Called when a media player wants to release current external video surface.
+     */
     @CalledByNative
     protected void destroy() {
         releaseExternalVideoSurface(mPlayerId);