diff --git a/RELEASENOTES.md b/RELEASENOTES.md
index 0fef76f737..349b904589 100644
--- a/RELEASENOTES.md
+++ b/RELEASENOTES.md
@@ -75,6 +75,11 @@
 * Add `Player.onPlaybackSuppressionReasonChanged` to allow listeners to
   detect playbacks suppressions (e.g. audio focus loss) directly
   ([#6203](https://github.com/google/ExoPlayer/issues/6203)).
+* VP9 extension:
+  * Rename `VpxVideoSurfaceView` to `VideoDecoderSurfaceView`
+    and move it to the core library.
+  * Move `LibvpxVideoRenderer.MSG_SET_OUTPUT_BUFFER_RENDERER` to
+    `C.MSG_SET_OUTPUT_BUFFER_RENDERER`.
 
 ### 2.10.5 (2019-09-20) ###
 
diff --git a/extensions/vp9/src/androidTest/java/com/google/android/exoplayer2/ext/vp9/VpxPlaybackTest.java b/extensions/vp9/src/androidTest/java/com/google/android/exoplayer2/ext/vp9/VpxPlaybackTest.java
index ff5d60a74a..3dd039118c 100644
--- a/extensions/vp9/src/androidTest/java/com/google/android/exoplayer2/ext/vp9/VpxPlaybackTest.java
+++ b/extensions/vp9/src/androidTest/java/com/google/android/exoplayer2/ext/vp9/VpxPlaybackTest.java
@@ -23,6 +23,7 @@ import android.net.Uri;
 import android.os.Looper;
 import androidx.test.core.app.ApplicationProvider;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
+import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.ExoPlaybackException;
 import com.google.android.exoplayer2.ExoPlayer;
 import com.google.android.exoplayer2.Player;
@@ -122,7 +123,7 @@ public class VpxPlaybackTest {
               .createMediaSource(uri);
       player
           .createMessage(videoRenderer)
-          .setType(LibvpxVideoRenderer.MSG_SET_OUTPUT_BUFFER_RENDERER)
+          .setType(C.MSG_SET_OUTPUT_BUFFER_RENDERER)
           .setPayload(new VideoDecoderSurfaceView(context))
           .send();
       player.prepare(mediaSource);
diff --git a/extensions/vp9/src/main/java/com/google/android/exoplayer2/ext/vp9/LibvpxVideoRenderer.java b/extensions/vp9/src/main/java/com/google/android/exoplayer2/ext/vp9/LibvpxVideoRenderer.java
index 79d1d2e66f..fe59031429 100644
--- a/extensions/vp9/src/main/java/com/google/android/exoplayer2/ext/vp9/LibvpxVideoRenderer.java
+++ b/extensions/vp9/src/main/java/com/google/android/exoplayer2/ext/vp9/LibvpxVideoRenderer.java
@@ -48,20 +48,13 @@ import com.google.android.exoplayer2.video.VideoRendererEventListener;
  * <ul>
  *   <li>Message with type {@link C#MSG_SET_SURFACE} to set the output surface. The message payload
  *       should be the target {@link Surface}, or null.
- *   <li>Message with type {@link #MSG_SET_OUTPUT_BUFFER_RENDERER} to set the output buffer
+ *   <li>Message with type {@link C#MSG_SET_OUTPUT_BUFFER_RENDERER} to set the output buffer
  *       renderer. The message payload should be the target {@link
  *       VideoDecoderOutputBufferRenderer}, or null.
  * </ul>
  */
 public class LibvpxVideoRenderer extends SimpleDecoderVideoRenderer {
 
-  /**
-   * The type of a message that can be passed to an instance of this class via {@link
-   * ExoPlayer#createMessage(Target)}. The message payload should be the target {@link
-   * VideoDecoderOutputBufferRenderer}, or null.
-   */
-  public static final int MSG_SET_OUTPUT_BUFFER_RENDERER = C.MSG_CUSTOM_BASE;
-
   /** The number of input buffers. */
   private final int numInputBuffers;
   /**
@@ -298,7 +291,7 @@ public class LibvpxVideoRenderer extends SimpleDecoderVideoRenderer {
   public void handleMessage(int messageType, @Nullable Object message) throws ExoPlaybackException {
     if (messageType == C.MSG_SET_SURFACE) {
       setOutput((Surface) message, null);
-    } else if (messageType == MSG_SET_OUTPUT_BUFFER_RENDERER) {
+    } else if (messageType == C.MSG_SET_OUTPUT_BUFFER_RENDERER) {
       setOutput(null, (VideoDecoderOutputBufferRenderer) message);
     } else if (messageType == C.MSG_SET_VIDEO_FRAME_METADATA_LISTENER) {
       frameMetadataListener = (VideoFrameMetadataListener) message;
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/C.java b/library/core/src/main/java/com/google/android/exoplayer2/C.java
index c8a73fbe9a..b235715f46 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/C.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/C.java
@@ -27,6 +27,8 @@ import androidx.annotation.IntDef;
 import com.google.android.exoplayer2.PlayerMessage.Target;
 import com.google.android.exoplayer2.audio.AuxEffectInfo;
 import com.google.android.exoplayer2.util.Util;
+import com.google.android.exoplayer2.video.SimpleDecoderVideoRenderer;
+import com.google.android.exoplayer2.video.VideoDecoderOutputBufferRenderer;
 import com.google.android.exoplayer2.video.VideoFrameMetadataListener;
 import com.google.android.exoplayer2.video.spherical.CameraMotionListener;
 import java.lang.annotation.Documented;
@@ -823,6 +825,13 @@ public final class C {
    */
   public static final int MSG_SET_CAMERA_MOTION_LISTENER = 7;
 
+  /**
+   * The type of a message that can be passed to a {@link SimpleDecoderVideoRenderer} via {@link
+   * ExoPlayer#createMessage(Target)}. The message payload should be the target {@link
+   * VideoDecoderOutputBufferRenderer}, or null.
+   */
+  public static final int MSG_SET_OUTPUT_BUFFER_RENDERER = 8;
+
   /**
    * Applications or extensions may define custom {@code MSG_*} constants that can be passed to
    * {@link Renderer}s. These custom constants must be greater than or equal to this value.