DialogSurfaceManager implementation.

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

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.media;
+
+import android.os.IBinder;
+
+/**
+ * Class to facilitate mapping (pid, render_frame_id) to an Activity.  Should
+ * also handle registering for changes if the render frame is re-parented to
+ * another activity.
+ *
+ * Right now, all of this works on (pid, renderFrameId) pairs.  For security,
+ * we might want to switch to some sort of token that's acquired by the renderer
+ * and sent to the DialogSurface.  Otherwise, the GPU process can guess at
+ * renderFrameIds for any renderer pid.
+ *
+ * Note also that using pids introduces a race condition, in that one renderer
+ * might fail and be replced with another with the same pid.
+ */
+interface IDialogSurfaceActivityMapper {
+    /**
+     * Return the window token for the activity that hosts (rendererPid,
+     * renderFrameId).  This may return null.
+     */
+    IBinder getWindowToken(int rendererPid, int renderFrameId);
+}