Add support for tab migration to DialogSurface

media/base/android/java/src/org/chromium/media/IDialogSurfaceActivityMapper.aidl

Index: media/base/android/java/src/org/chromium/media/IDialogSurfaceActivityMapper.aidl
diff --git a/media/base/android/java/src/org/chromium/media/IDialogSurfaceActivityMapper.aidl b/media/base/android/java/src/org/chromium/media/IDialogSurfaceActivityMapper.aidl
index 96e38d7ea9a14c3c87a0dc6c3a039cc6cd3ba4ef..27b34745e882ecdb94a3641610f1b8cb92e464de 100644
--- a/media/base/android/java/src/org/chromium/media/IDialogSurfaceActivityMapper.aidl
+++ b/media/base/android/java/src/org/chromium/media/IDialogSurfaceActivityMapper.aidl
@@ -27,7 +27,14 @@ interface IDialogSurfaceActivityMapper {
     /**
      * Eventually call back holder::onWindowToken with the window token for the
      * activity that hosts (rendererPid, renderFrameId).  This will call back,
-     * but may call back with null.
+     * but may call back with null.  It may call back more than once if the
+     * token changes.
      */
-    void postWindowToken(int rendererPid, int renderFrameId, IDialogSurfaceHolder holder);
+    void registerHolder(int rendererPid, int renderFrameId, IDialogSurfaceHolder holder);
+
+    /**
+     * Unregister holder for callbacks.  Some callbacks may be in-flight, and
+     * could arrive after this returns.
+     */
+    void unregisterHolder(IDialogSurfaceHolder holder);
 }